mnttab(4)
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mnttab File Format
mounted file system table in DG/UX
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SYNTAX
#include <mnttab.h>
DESCRIPTION
Mnttab resides in the directory /etc and consists of a list of
currently mounted file systems. The file contains a number of
lines like this:
fsname dir type opts freq passno
for example:
/dev/dsk/usr /usr dg/ux rw 1 1
would indicate a mount for a local filesystem, and
titan:/usr/titan /usr/titan nfs rw,hard 0 0
would indicate an NFS filesystem mount. The entries from this
file are accessed using the routines in getmntent(3), which
returns a structure of the following form:
struct mntent {
char *mnt_fsname; /* filesystem name */
char *mnt_dir; /* filesystem path prefix */
char *mnt_type; /* dg/ux, nfs, swap, or ignore */
char *mnt_opts; /* rw, ro, hard, soft */
int mnt_freq; /* highest dump level */
int mnt_passno; /* pass number on parallel fsck */
};
Fields are separated by white space; a #, as the first non-white
character, indicates a comment. The mnt_type field determines
how the mnt_fsname and mnt_opts fields will be interpreted. The
following is a list of the filesystem types currently supported,
and the way each of them interprets these fields:
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mnttab(4)
Type Field Interpretation
dg/ux mnt_fsname Must be a block special
device.
mnt_opts Valid options are ro, rw.
nfs mnt_fsname The hostname of the server and
the pathname on the server of
the directory to be served. A
colon separates the pathname
and hostname.
mnt_opts Valid options are ro, rw,
hard, soft.
swap mnt_fsname Must be a block special device
swap section.
mnt_opts Ignored.
If the mnt_type is specified as ignore then the entry is ignored.
This is useful to show disks not currently used.
Entries identified as swap are made available as swap space by
the swapon(1m) command at the end of the system reboot procedure.
When the mnt_fsname field is interpreted as a block special
device, programs that require the corresponding character special
device must construct the name by changing dsk to rdsk in the
pathname.
If the mnt_opts field is a comma-separated list of options that
includes ro or rw, then the filesystem is mounted read-write or
read-only. If this includes hard or soft, then the NFS
filesystem is mounted hard or soft.
The field mnt_freq indicates how often each filesystem should be
dumped by the dump(1m) command (and triggers that command's w
option, which determines what filesystems should be dumped).
Most systems set the mnt_freq field to 1, indicating that
filesystems are dumped each day.
The final field mnt_passno is used by the consistency checking
program fsck(1m) to allow overlapped checking of filesystems
during a reboot. All filesystems with a mnt_passno of 1 are
checked first simultaneously, then all filesystems with
mnt_passno of 2 are checked, and so on. The <mnt_passno> of the
root filesystem should be 0, as the root cannot be checked since
it is already mounted.
The maximum number of entries in mnttab is based on the system
parameter NMOUNT located in /usr/src/uts/mv/cf/config.h, which
defines the number of allowable mounted special files.
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mnttab(4)
SEE ALSO
mount(1m), setmnt(1m) in the System Manager's Reference for the
DG/UX System.
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