mnttab(4) DG/UX 4.30 mnttab(4)
NAME
mnttab - mounted file system table in DG/UX
SYNOPSIS
#include <mntent.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, cdrom, or ignore */
char *mnt_opts; /* rw, ro, hard, soft, fg, bg, memory */
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) DG/UX 4.30 mnttab(4)
Type Field Interpretation
dg/ux mnt_fsname Must be a block special
device.
mnt_opts Valid options are ro, rw, bg,
and fg. If this has the
ramdisk option, other options
include use_wired_memory,
max_file_space and
max_file_count.
cdrom mnt_fsname Must be a block special
device.
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
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mnttab(4) DG/UX 4.30 mnttab(4)
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.
SEE ALSO
mount(1M), setmnt(1M) in the System Manager's Reference for
the DG/UX System.
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