871 lines
25 KiB
Groff
871 lines
25 KiB
Groff
.TH fstab 4
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.SH NAME
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fstab \- static information about filesystems
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.SH DESCRIPTION
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The file
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.I /etc/fstab
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describes the filesystems
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and swapping partitions
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used by the local machine.
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The system administrator can modify it with a text editor.
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It is read by commands that mount, unmount,
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and check the consistency of filesystems.
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The file consists of a number of lines of the form:
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.Ex
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\f2filesystem\ \ directory\ \ type\ \ options\ \ frequency\ \ pass\f1
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.Ee
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For example:
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.Ex
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/dev/root\ \ \ /\ \ \ xfs\ \ \ rw\ \ 0 0
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.Ee
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Fields are separated by white space;
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a `#' as the first non-white space character indicates a comment.
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.PP
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The entries from this file are accessed using the routines in
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.IR getmntent (3),
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which return a structure of the following form:
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.Ex
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struct mntent {
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char *mnt_fsname; /* filesystem name */
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char *mnt_dir; /* filesystem path prefix */
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char *mnt_type; /* e.g. xfs, nfs, proc, or ignore */
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char *mnt_opts; /* rw, ro, hard, soft, etc. */
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int mnt_freq; /* dump frequency, in days */
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int mnt_passno; /* parallel fsck pass number */
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};
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.Ee
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This structure is defined in the
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.I <mntent.h>
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include file.
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To compile and link a program that calls
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.IR getmntent (3),
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follow the procedures for section (3Y) routines as
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described in
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.IR intro (3).
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.PP
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The
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.I mnt_dir
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field is the full pathname of the directory to be mounted on.
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The
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.I mnt_type
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field determines how the
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.I mnt_fsname
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and
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.I mnt_opts
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fields are interpreted.
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Here is a list of the filesystem types currently supported,
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and the way each of them interprets these fields:
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.TP 10
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.B xfs
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\f2mnt_fsname\f1 must be a block special device (for example,
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.IR /dev/root )
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or a logical volume.
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.TP 10
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.B efs
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\f2mnt_fsname\f1 must be a block special device (for example,
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.IR /dev/root )
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or a logical volume.
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.TP 10
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.B proc
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\f2mnt_fsname\f1 should be the
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.I /proc
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directory.
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See
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.IR proc (4).
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.TP 10
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.B fd
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\f2mnt_fsname\f1 should be the
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.I /dev/fd
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directory.
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See
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.IR fd (4).
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.TP 10
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.B hwgfs
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\f2mnt_fsname\f1 should be the
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.I /hw
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directory.
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See
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.IR hwgfs (4).
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.TP 10
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.B nfs
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\f2mnt_fsname\f1 is the path on the server of the directory to be served.
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(NFS option only).
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.TP 10
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.B cdfs
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A synonym for type
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.B iso9660
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(see below).
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This type is required for MIPS ABI compliance.
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.TP 10
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.B iso9660
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\f2mnt_fsname\f1 formerly was a generic SCSI device. With 6.2
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plus patches, or later releases, it is the volume partition of
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the raw disk
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(for example,
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.IR /dev/rdsk/dks0d7vol ).
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See
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.IR ds (7M).
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This filesystem type is used to mount CD-ROM discs in
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ISO 9660 (with or without Rock Ridge
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extensions) and High Sierra formats.
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\f2eoe.sw.cdrom\f1 must be installed in order to use
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the \f3iso9660\f1 filesystem type.
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.TP 10
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.B dos
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\f2mnt_fsname\f1 is normally a floppy device, or other
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removable media using the disk driver.
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These are located in the directory
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.I /dev/rdsk
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(for example,
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.IR /dev/rdsk/fds0d2.3.5 ).
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See
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.IR dksc (7M)
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and
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.IR smfd (7M).
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.TP 10
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.B hfs
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\f2mnt_fsname\f1 must be either a floppy device or a raw disk
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device.
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Floppy devices are located in the directory
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.I /dev/rdsk
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(for example,
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.IR /dev/rdsk/fds0d2.3.5hi ).
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See
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.IR smfd (7M).
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Raw disk devices are located in the directory
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.I /dev/rdsk
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(for example,
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.IR /dev/rdsk/dks0d4vol ).
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See
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.IR ds (7M).
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.TP
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.B swap
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\f2mnt_fsname\f1 should be the full pathname to the file or block device
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to be used as a swap resource.
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.TP
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.B cachefs
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\f2mnt_fsname\f1 should be the filesystem name for the backing filesystem
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to be mounted as a cache filesystem.
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This will either be the special filename (for example,
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.IR /dev/dsk/dks0d4s7 )
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or
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.IR host : path .
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.TP 10
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.B rawdata
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\f2mnt_fsname\f1 may be the block/char special device of the partition
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or logical volume to reserve (\f2mnt_dir\f1 is ignored).
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This entry
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enables the system utilities (for example,
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.IR mkfs ,
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.IR mount ,
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and so on) to treat the raw
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partition or logical volume
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as 'mounted', preventing the partition from inadvertently being overwritten.
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Any packages that require dedicated raw partitions (databases and so on) should
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consider placing a
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.B rawdata
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entry in
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.IR fstab (4).
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.PP
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If the \f2mnt_type\f1 is specified as
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.BR ignore ,
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then the entry is ignored.
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This is useful to show disk partitions not currently used.
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.I mnt_freq
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is not used in current IRIX systems.
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.PP
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.I mnt_passno
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can be used to control the behavior of parallel filesystem checking on
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bootup, see
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.IR fsck (1M).
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.PP
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The
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.I mnt_opts
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field contains a list of comma-separated option words.
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Some
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.I mnt_opts
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are valid for all filesystem types, while others apply to a
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specific type only.
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.PP
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Options valid on
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all
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filesystems (the default is
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.BR rw )
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are:
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.IP \f3rw\f1 10
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Read/write.
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.IP \f3ro\f1
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Read-only.
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.IP \f3noauto\f1
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Ignore this entry during a \f2mount\f1 \f3\-a\f1 command,
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to allow the definition of
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\f2fstab\f1 entries for commonly-used filesystems that should not be
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automatically mounted.
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.IP \f3grpid\f1
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Causes a file created within the filesystem to have the group ID of its
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parent directory, not the creating process's group ID.
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.IP \f3nosuid\f1
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Setuid execution not allowed for non-superusers.
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This option has no effect
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for the superuser.
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.IP \f3nodev\f1
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Access to character and block special files is disallowed.
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.PP
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Mandatory Access Control options can be specified using a list of
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colon-separated options:
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.ce
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\f3eag\f1:\f2option\f1{:\f2option\f1 ...}
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.br
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where \f2option\f1 is one of the following:
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.IP \f3mac-default\f1=\f2label\f1
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Use the specified label for all files on the specified file system
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that do not have a MAC label.
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.IP \f3mac-ip\f1=\f2label\f1
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Use the specified label for communications to other systems regarding this file system.
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.PP
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A number of filesystem types also support the \f3debug\fP option, but the
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meaning varies with the filesystem type.
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.PP
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Options specific only to
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.B xfs, efs
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and
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.B nfs
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filesystems are:
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.IP \f3quota\f1 10
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Disk quota accounting enabled, and limits enforced.
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.PP
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Options specific to
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.B xfs
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filesystems are:
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.IP \f3biosize\f1 10
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The biosize (buffered I/O size) option can be used to
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set the default preferred buffered I/O size for filesystem.
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The default preferred I/O size is 64K.
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The biosize option can be used to decrease the preferred I/O
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size.
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The size must be expressed as the log (base2) of the desired
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I/O size.
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Valid values for this option are 14 through 16, inclusive
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(e.g. 16K, 32K, and 64K bytes).
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On machines with 4K size pages, 13 (8 Kbytes) is also a valid size.
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The preferred buffered I/O size can also be altered
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on a per-file basis using the \f2fcntl\fP system call.
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See \f2fcntl\fP(2) for further details.
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.IP \f3dmi\f1 10
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Enable the Data Management Interface event callouts.
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.IP \f3logbufs\f1 10
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Set the number of in memory log buffers.
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Valid numbers range from 2-8 inclusive.
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The default value is 8 buffers for filesystems with a blocksize of 64K,
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4 buffers for filesystems with a blocksize of 32K,
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3 buffers for filesystems with a blocksize of 16K,
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and 2 buffers for all other configurations.
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Increasing the number of buffers may increase performance on
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some workloads at the cost of the memory used for the extra
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log buffers and their associated control structures.
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.IP \f3noalign\f1
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Data allocations will not be aligned at stripe unit boundaries.
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.IP \f3noatime\f1
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Access timestamps are not updated when a file is read.
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.IP \f3norecovery\f1
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The filesystem will be mounted without running log recovery.
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If the filesystem was not cleanly unmounted, it is likely to
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be inconsistent when mounted in norecovery mode.
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Some files or directories may not be accessible because of this.
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Filesystems mounted norecovery must be mounted read-only
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or the mount will fail.
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.IP \f3osyncisdsync\f1 10
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Make writes to files opened with the O_SYNC flag set behave
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as if the O_DSYNC flag had been used instead.
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This can result in better performance without compromising
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data safety.
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However if this option in effect, timestamp updates from
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O_SYNC writes can be lost if the system crashes.
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.IP \f3qnoenforce\f1
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Disk quota accounting enabled, but limits are not enforced.
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.IP \f3sunit\f1=\f2value\f1 10
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Used to specify the stripe unit for a RAID device or a xlv stripe volume.
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\f2value\f1 has to be specified in 512-byte block units.
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If this option is not
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specified and the filesystem was made on a stripe volume or the stripe
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unit was specified for the RAID device at mkfs time, then the mount system
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call will restore the value from the superblock. For filesystems that are
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made directly on RAID devices, this option can be used to override the
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information in the superblock if the underlying disk layout changes after
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the filesystem has been mkfsed. If the filesystem is made on a xlv volume,
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then this will be done implicitly.
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.IP \f3swidth\f1=\f2value\f1 10
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Used to specify the stripe width for a RAID device or a xlv stripe volume.
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\f2value\f1 has to be specified in 512-byte block units.
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If this option is not
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specified, and the filesystem was made on a stripe volume or the stripe
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width was specified for the RAID device at mkfs time, then the mount system
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call will restore the value from the superblock. For filesystems that are
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made directly on RAID devices, this option can be used to override the
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information in the superblock if the underlying disk layout changes after
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the filesystem has been mkfsed. If the filesystem is made on a xlv volume,
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then this will be done implicitly. This option is required if the
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.B -o sunit
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option has been specified. Also it has to be a multiple of the sunit option.
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.IP \f3wsync\f1
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All operations that modify the filesystem are synchronous
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except for writes to user files (e.g. create, unlink, mv, truncate, etc.).
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This option can be used in conjunction with exporting a filesystem -wsync
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to obtain NFS write-synchronous semantics, if so desired.
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See \f3exports(4)\f1 for further information.
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.PP
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Options specific to
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.B efs
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filesystems (the default is
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.BR fsck ,
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.BR noquota )
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are:
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.IP \f3raw\f1=\f2path\f1 10
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The filesystem's raw device pathname (for example,
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.IR /dev/rroot ).
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.IP \f3fsck\f1
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.IR fsck (1M)
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invoked with no filesystem arguments should check this filesystem.
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.IP \f3nofsck\f1
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.IR fsck (1M)
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should not check this filesystem by default.
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.IP \f3noquota\f1
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Disk quota accounting and limit enforcement disabled.
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.IP \f3lbsize\f1=\f2n\f1
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The number of bytes transferred in each read or synchronous write operation.
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.\" .IP \f3pbsize\f1=\f2n\f1 .75i
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.\" the file preallocation size.
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.\" Whenever a file is grown, \f2pbsize\fP contiguous bytes (if available) are
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.\" preallocated for the file;
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.\" when the file is closed (see \f3close(2)\fP), unused blocks are deallocated.
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.\" This value has size restrictions similar to \f3lbsize\fP;
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.\" in addition, it cannot be greater than the number of data blocks
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.\" in a cylinder group (see \f3efs(4)\fP).
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.\" By default, \f3pbsize\fP is the same as \f3lbsize\f1.
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.\" Note that this value effectively limits \f3lbsize\fP during write operations
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.\" that grow a file.
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.IP
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The value assigned to the
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.B lbsize
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option must be a power of two at least as large as
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the system page size.
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This value is returned by the
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.IR getpagesize (2)
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system call and is normally either 4096 or 16384 depending
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on the system type.
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The current default for
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.B lbsize
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is the value in the fs_sectors field of the superblock of the filesystem.
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This was normally the number of "sectors per track" in the past, but
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that often fictious value is no longer used. If not set on the mkfs
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command line, the maximum value of 128 sectors is used by IRIX 6.4
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and later releases.
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An invalid size will cause the mount to fail with the error EINVAL.
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The maximum size is currently 65536.
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Note that less than
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.B lbsize
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bytes will be transferred if there are not
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.B lbsize
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contiguous bytes of the addressed portion of the file on disk.
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.PP
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Options specific to
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.B dos
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filesystems.
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.IP \f3partition\fP
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With a following number, as \f3partition,#\fP, where \f3#\fP is most often
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either 1 or 4, is used with type 5 (extended) filesystems
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to specify which partition to use. Otherwise type 5 filesystems
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are not supported.
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.PP
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Options specific to
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.B iso9660
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filesystems (the default is
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.BR rw ,
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which has no effect since CD-ROM discs are always read-only) are:
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.IP \f3setx\f1 10
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Set execute permission on every file on the mounted
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filesystem.
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The default is to
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make an intelligent guess based on the first few bytes of the file.
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.IP \f3notranslate\f1
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Don't translate ISO 9660 filenames to UNIX filenames.
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The default is to convert upper case to lower case and to
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truncate the part including and after the semicolon.
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.IP \f3cache\f1=\f2blocks\f1
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Set the number of 2048 byte blocks to be used for caching
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directory contents.
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The default is to cache 128 blocks.
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.IP \f3noext\f1
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Ignore Rock Ridge extensions.
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The default when the \f3noext\f1 option
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is not specified is to use Rock Ridge extensions
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if present.
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.IP \f3susp\f1
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Enable processing of System Use Sharing Protocol extensions to the
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ISO 9660 specification.
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This is the default.
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.IP \f3nosusp\f1
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Disable processing of System Use Sharing Protocol extensions.
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This
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has the same effect as the \f3noext\f1 option.
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.IP \f3rrip\f1
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Enable processing of the Rock Ridge extensions.
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This is the default.
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.IP \f3norrip\f1
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Disable processing of the Rock Ridge extensions.
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This is equivalent
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to the \f3noext\f1 option.
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.IP \f3nmconv=[clm]\f1
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This option is supplied for MIPS ABI compliance; some non-IRIX systems may
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implement it only for type
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.BR cdfs ,
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IRIX allows it with type
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.B iso9660
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also.
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Only one of the three letters
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.BR c ,
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.BR l ,
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or
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.B m
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can be specified.
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This option controls filename translation.
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.B c
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has the same meaning as \f3notranslate\f1 above.
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.B l
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requests translation to lower case (the IRIX default), and
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.B m
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suppresses the version number (also the IRIX default).
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.PP
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NFS clients can mount \f3iso9660\f1, \f3dos\f1, and \f3hfs\f1 filesystems
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remotely by specifying \f2hostname\f1:\f2mountpoint\f1 for
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\f2filesystem\f1 and \f3nfs\f1 for \f2type\f1, where an \f3iso9660\f1,
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\f3dos\f1, or \f3hfs\f1 filesystem is mounted at \f2mountpoint\f1 on the
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host \f2hostname\f1.
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In this case, the same \f2options\f1 apply
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as with \f3nfs\f1 (see below).
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.PP
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If the NFS option is installed, the following options
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are valid for
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.B nfs
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filesystems:
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.IP \f3vers=\f2n\f1 10
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Use NFS protocol version
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.IR n .
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(The default is to try version 3, falling back to version 2 if the
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version 3 mount
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fails.)
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.IP \f3bg\f1 10
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If the first attempt fails, retry in the background.
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.IP \f3fg\f1
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Retry in foreground.
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(Default)
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.IP \f3retry=\f2n\f1
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Set number of mount failure retries to
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.IR n .
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(Default = 10000)
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.IP \f3rsize=\f2n\f1
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Set read transfer size to
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.I n
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bytes. This value will be rounded up to the nearest multiple
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of 512 bytes.
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The default is 8192 for NFS version 2, and 16384 or
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32768 for NFS version 3. The 16KB transfer size is used
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when the route to the server is known to go through a router,
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or when the Maximum Transmission Unit (MTU) of the
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interface used to get to the server is Ethernet-sized
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(about 1500 bytes) or less.
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The system tunable
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\f3nfs3_default_xfer\f1
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can be used to reduce the upper limit of the NFS version 3
|
|
transfer size if 16KB is still too much for routers.
|
|
For example, setting it to 8192 gives the same default for
|
|
version 3 as version 2.
|
|
For NFS version 3, the read transfer size specified by the server will
|
|
be used if it is smaller than either the default or what the user
|
|
has specified.
|
|
.IP \f3wsize=\f2n\f1
|
|
Set write transfer size to
|
|
.I n
|
|
bytes. This value will be rounded up to the nearest multiple
|
|
of 512 bytes. The default is the same as for the read size.
|
|
For NFS version 3, the write transfer size specified by the server will
|
|
be used if it is smaller than either the default or what the user
|
|
has specified.
|
|
.IP \f3timeo=\f2n\f1
|
|
Set NFS timeout to
|
|
.I n
|
|
tenths of a second.
|
|
(Default = 11)
|
|
.IP \f3retrans=\f2n\f1
|
|
Set number of NFS retransmissions to
|
|
.IR n .
|
|
(Default = 5)
|
|
.IP \f3port=\f2n\f1
|
|
Set server UDP port number to
|
|
.IR n .
|
|
(Default = 2049)
|
|
.IP \f3hard\f1
|
|
Retry request until server responds.
|
|
(Default)
|
|
.IP \f3soft\f1
|
|
Return error if server doesn't respond.
|
|
.IP \f3nointr\f1
|
|
Disallow requests to be interrupted by the following signals:
|
|
SIGHUP, SIGINT, SIGQUIT, SIGKILL, SIGTERM, and SIGTSTP.
|
|
(Requests are interruptible by these signals, by default.)
|
|
.IP \f3acregmin\f1=\f2t\f1
|
|
Set the regular file minimum attribute cache timeout to
|
|
.I t
|
|
seconds.
|
|
(Default = 3)
|
|
.IP \f3acregmax\f1=\f2t\f1
|
|
Set the regular file maximum attribute cache timeout to
|
|
.I t
|
|
seconds.
|
|
(Default = 60)
|
|
.IP \f3acdirmin\f1=\f2t\f1
|
|
Set the directory minimum attribute cache timeout to
|
|
.I t
|
|
seconds.
|
|
(Default = 30)
|
|
.IP \f3acdirmax\f1=\f2t\f1
|
|
Set the directory maximum attribute cache timeout to
|
|
.I t
|
|
seconds.
|
|
(Default = 60)
|
|
.IP \f3actimeo\f1=\f2t\f1
|
|
Set regular and directory minimum and maximum attribute cache timeouts to
|
|
.I t
|
|
seconds.
|
|
.IP \f3noac\f1
|
|
No attribute caching.
|
|
.IP \f3proto\f1=\f2xyz\f1
|
|
Use the IP protocol
|
|
.I xyz
|
|
, where
|
|
.I xyz
|
|
is either
|
|
.I udp
|
|
or
|
|
.I tcp .
|
|
If the specified protocol is not supported by the server, then the
|
|
mount will fail. The default is
|
|
.I udp .
|
|
.IP \f3private\f1
|
|
Do not flush delayed writes on last close of an open file, and use local
|
|
file and record locking instead of a remote lock manager.
|
|
.IP \f3shortuid\f1
|
|
Do not let users with userids or groupids larger than 65535 (see
|
|
.IR id (1M))
|
|
create or own files.
|
|
Some versions of UNIX do not support large userids;
|
|
trying to create a file with a large userid on such an NFS server can
|
|
produce undefined and surprising results.
|
|
.IP \f3symttl\f1=\f2t\f1
|
|
Set the time-to-live for symbolic links cached by NFS to
|
|
.I t
|
|
seconds.
|
|
\f3symttl=0\f1 turns off NFS symlink caching.
|
|
The maximum value for
|
|
.I t
|
|
is 3600.
|
|
(Default = 3600)
|
|
.IP \f3asyncnlm\f1
|
|
Use asynchronous NLM RPC calls.
|
|
The default is to use synchronous NLM.
|
|
Using this option requires that
|
|
.IR lockd (1M)
|
|
be running.
|
|
.IP \f3defxattr\f1
|
|
Use default values for system\-defined extended attributes, rather than asking
|
|
the NFS server for their values. This option does not work when \f3noac\f1
|
|
is also specified.
|
|
.IP \f3doxattr\f1
|
|
Tell the NFS server that this client can be trusted to properly handle extended
|
|
attributes. This is necessary only when the remote filesystem is exported with
|
|
the \f3noxattr\f1 option.
|
|
.PP
|
|
The
|
|
.B bg
|
|
option causes
|
|
.I mount
|
|
to run in the background if the server's
|
|
.IR mountd (1M)
|
|
does not respond.
|
|
.I mount
|
|
attempts each request
|
|
.BI retry= n
|
|
times before giving up.
|
|
.PP
|
|
Once the filesystem is mounted, each NFS
|
|
request waits
|
|
.BI timeo= n
|
|
tenths of a second for a response.
|
|
If no response arrives, the
|
|
time-out is multiplied by 2, up to a maximum of MAXTIMO (900),
|
|
and the request is retransmitted.
|
|
When
|
|
.BI retrans= n
|
|
retransmissions have been sent with no reply a
|
|
.B soft
|
|
mounted filesystem returns an error on the request and a
|
|
.B hard
|
|
mounted filesystem retries the request.
|
|
Filesystems that are mounted
|
|
.B rw
|
|
(read-write)
|
|
should use the
|
|
.B hard
|
|
option.
|
|
The number of bytes in a read or write request can be set with the
|
|
.B rsize
|
|
and
|
|
.B wsize
|
|
options.
|
|
.PP
|
|
In the absence of client activity that would invalidate recently acquired
|
|
file attributes, NFS holds attributes cached for an interval between
|
|
.B acregmin
|
|
and
|
|
.B acregmax
|
|
for regular files, and between
|
|
.B acdirmin
|
|
and
|
|
.B acdirmax
|
|
for directories.
|
|
The
|
|
.B actimeo
|
|
option sets all attribute timeout constraints to a given number of seconds.
|
|
The
|
|
.B noac
|
|
option disables attribute caching altogether.
|
|
.LP
|
|
The
|
|
.B private
|
|
option greatly improves write performance by caching data and delaying
|
|
writes on the assumption that only this client modifies files in the remote
|
|
filesystem.
|
|
It should be used only if the greater risk of lost delayed-write data in the
|
|
event of a crash is acceptable given better performance.
|
|
EFS uses caching strategies similar to private NFS
|
|
The
|
|
system reduces the risk of data loss for all filesystems by automatically
|
|
executing a partial
|
|
.IR sync (2)
|
|
at regular intervals.
|
|
.PP
|
|
If the BDS option is installed, the following options
|
|
are valid for
|
|
.B nfs
|
|
filesystems that have BDS service enabled:
|
|
.IP \f3bds\f1 10
|
|
Turn on bulk data service for this file system.
|
|
.IP \f3bdsauto\f1=\f2size\f1 10
|
|
For all read/write requests that are sized greater
|
|
or equal to \f2size\f1, do BDS I/O instead of NFS I/O.
|
|
.IP \f3bdswindow\f1=\f2size\f1 10
|
|
Set the TCP protocol send and receive windows to \f2size\f1 instead of the
|
|
default of 4Mbytes.
|
|
.IP \f3bdsbuffer\f1=\f2size\f1 10
|
|
Specify the size of data buffers within the server, instead of
|
|
allowing the server to determine the best size.
|
|
.PP
|
|
Options specific to
|
|
.B swap
|
|
resources are:
|
|
.IP \f3pri\f1=\f2t\f1 10
|
|
Set the priority of the swap device to \f2t\f1.
|
|
The legal values are from
|
|
0 to 7 inclusive.
|
|
.IP \f3swplo\f1=\f2t\f1
|
|
Set the first 512 byte block to use to \f2t\f1 (default is 0).
|
|
.IP \f3length\f1=\f2t\f1
|
|
Set the number of 512 byte blocks to use to \f2t\f1 (default is entire
|
|
file/partition).
|
|
.IP \f3maxlength\f1=\f2t\f1
|
|
Set the maximum number of 512 byte blocks to grow the swap area to \f2t\f1
|
|
(default is to use \f3length\f1).
|
|
.IP \f3vlength\f1=\f2t\f1
|
|
Set the number of virtual 512 byte blocks to
|
|
claim this swap file has to \f2t\f1 (default is to use
|
|
\f3length\f1).
|
|
.PP
|
|
All other options except for \f2noauto\f1 are ignored for \f4swap\f1
|
|
files.
|
|
.PP
|
|
If the CacheFS option is installed, the following options are valid for
|
|
.B cachefs
|
|
filesystems:
|
|
.IP \f3backfstype\f1=\f2file_system_type\f1 10
|
|
The filesystem type of the back filesystem (for example, \f3nfs\f1).
|
|
Any of the following filesystem types may be used as the back filesystem:
|
|
.IR nfs ,
|
|
.IR nfs3 ,
|
|
.IR iso9660 ,
|
|
.IR dos ,
|
|
.IR cdfs ,
|
|
.IR kfs ,
|
|
or
|
|
.IR hfs .
|
|
If this option is not specified, the back filesystem type is determined
|
|
from the filesystem name.
|
|
Filesystem names of the form \f2hostname\f1:\f2path\f1 will
|
|
be assumed to be type
|
|
.IR nfs .
|
|
.IP \f3backpath\f1=\f2path\f1
|
|
Specifies where the back filesystem
|
|
is already mounted.
|
|
If this argument is not supplied,
|
|
CacheFS determines a mount point for the back filesystem.
|
|
.IP \f3cachedir\f1=\f2directory\f1
|
|
The name of the cache directory.
|
|
.IP \f3cacheid\f1=\f2ID\f1
|
|
.I ID
|
|
is a string specifying a particular instance of a cache.
|
|
If you do not specify a cache ID, CacheFS will construct one.
|
|
.IP \f3write-around\f1\ |\ \f3non-shared\f1
|
|
Write modes for CacheFS.
|
|
In the
|
|
.B write-around
|
|
mode, writes are made to the back filesystem,
|
|
and the affected file is purged from the cache.
|
|
Also in this mode,
|
|
file and record locking is performed through the back filesystem.
|
|
You can use the
|
|
.B non-shared
|
|
mode (the default) when you are sure that no one else will be
|
|
writing to the cached filesystem.
|
|
In this mode,
|
|
all writes are made to both the front and the back filesystem,
|
|
and the file remains in the cache.
|
|
.IP \f3noconst\f1
|
|
By default, consistency checking is performed.
|
|
Disable consistency checking by specifying
|
|
.B noconst
|
|
only if you mount the filesystem read-only.
|
|
.IP \f3private\f1
|
|
Causes file and record locking to be performed locally.
|
|
In addition,
|
|
files remain cached when file and record locking is performed.
|
|
By default,
|
|
files are not cached when file and record locking is performed and all
|
|
file and record locking is handled by the back filesystem.
|
|
.IP \f3local-access\f1
|
|
Causes the front filesystem to interpret the mode bits
|
|
used for access checking instead or having the back filesystem
|
|
verify access permissions.
|
|
.IP \f3suid\f1\ |\ \f3nosuid\f1
|
|
Allow (default) or disallow set-uid execution.
|
|
.IP \f3acregmin\f1=\f2n\f1
|
|
Specifies that cached attributes are held
|
|
for at least
|
|
.I n
|
|
seconds
|
|
after file modification.
|
|
After
|
|
.I n
|
|
seconds,
|
|
CacheFS checks to see
|
|
if the file modification time on the back filesystem has changed.
|
|
If it has, all information about the file is purged from the cache
|
|
and new data is retrieved from the back filesystem.
|
|
The default value is 30 seconds.
|
|
.IP \f3acregmax\f1=\f2n\f1
|
|
Specifies that cached attributes are held for no more than
|
|
.I n
|
|
seconds after file modification.
|
|
After
|
|
.I n
|
|
seconds, all file information is purged from the cache.
|
|
The default value is 30 seconds.
|
|
.IP \f3acdirmin\f1=\f2n\f1
|
|
Specifies that cached attributes are held
|
|
for at least
|
|
.I n
|
|
seconds after directory update.
|
|
After
|
|
.I n
|
|
seconds, CacheFS checks to see
|
|
if the directory modification time on the back filesystem has changed.
|
|
If it has, all information about the directory is purged from the cache
|
|
and new data is retrieved from the back filesystem.
|
|
The default value is 30 seconds.
|
|
.IP \f3acdirmax\f1=\f2n\f1
|
|
Specifies that cached attributes are held for no more than
|
|
.I n
|
|
seconds after directory update.
|
|
After
|
|
.I n
|
|
seconds, all directory information is purged from the cache.
|
|
The default value is 30 seconds.
|
|
.IP \f3actimeo\f1=\f2n\f1
|
|
Sets
|
|
.BR acregmin ,
|
|
.BR acregmax ,
|
|
.BR acdirmin ,
|
|
and
|
|
.B acdirmax
|
|
to
|
|
.IR n .
|
|
.IP \f3bg\f1
|
|
This option causes
|
|
.I mount
|
|
to run in the background if the back filesystem mount times out.
|
|
.IP \f3disconnect\f1
|
|
Causes the cache filesystem to operate in disconnected mode when the
|
|
back filesystem fails to respond.
|
|
This causes read accesses to files
|
|
already cached to be fulfilled from the front filesystem even when
|
|
the back filesystem does not respond.
|
|
.SH NOTES
|
|
The filesystem types \f3nfs2\f1, \f3nfs3\f1, and \f3nfs3pref\f1
|
|
are accepted for compatibility
|
|
with earlier releases.
|
|
\f3nfs2\f1 is equivalent to \f3vers=2\f1.
|
|
\f3nfs3\f1 is equivalent to \f3vers=3\f1.
|
|
\f3nfs3pref\f1 is equivalent to \f3nfs\f1 with no \f3vers=\f1 option.
|
|
.PP
|
|
Options used by the
|
|
.IR mount (1M)
|
|
command on normal filesystems are ignored when applied to the
|
|
root filesystem, since the \f2fstab\f1 file cannot be read before
|
|
mounting the root filesystem. These options include
|
|
.B rw
|
|
and
|
|
.B ro
|
|
(the root filesystem cannot be mounted read-only),
|
|
.BR grpid ,
|
|
.B quota
|
|
and
|
|
.B qnoenforce
|
|
(see
|
|
.IR quotaon (1M),
|
|
.BR dmi ,
|
|
.BR wsync ,
|
|
.BR noatime ,
|
|
.BR noalign ,
|
|
.BR sunit ,
|
|
.BR swidth ,
|
|
.BR noquota ,
|
|
and
|
|
.BR lbsize.
|
|
.SH FILES
|
|
/etc/fstab
|
|
.SH SEE ALSO
|
|
cfsadmin(1M),
|
|
fsck(1M),
|
|
mount(1M),
|
|
quotacheck(1M),
|
|
quotaon(1M),
|
|
swap(1M),
|
|
getmntent(3),
|
|
efs(4),
|
|
exports(4),
|
|
fd(4),
|
|
filesystems(4),
|
|
mtab(4),
|
|
proc(4),
|
|
xfs(4).
|