HP-UX Reference (11i v2 04/09) - 1M System Administration Commands A-M (vol 3)

m
mount_nfs(1M) mount_nfs(1M)
-h host Unmount only those file systems listed in
/etc/mnttab that are remote-mounted
from host.
-v Verbose mode. Write a message to standard output indicating which file system is
being unmounted.
-V Echo the completed command line, but performs no other action. The command line
is generated by incorporating the user-specified options and other information
derived from /etc/fstab. This option allows the user to verify the command
line.
NFS File Systems
Background vs. Foreground
File systems mounted with the bg option indicate that
mount is to retry in the background if the
server’s mount daemon (mountd(1M)) does not respond.
mount retries the request up to the count
specified in the
retry=n option. Once the file system is mounted, each NFS request made in the
kernel waits timeo=n tenths of a second for a response. If no response arrives, the time-out is
multiplied by 2 and the request is retransmitted. When the number of retransmissions has
reached the number specified in the
retrans=n option, a file system mounted with the soft
option returns an error on the request; one mounted with the
hard option prints a warning mes-
sage and continues to retry the request.
Hard vs. Soft
File systems that are mounted read-write or that contain executable files should always be mounted
with the
hard option. Applications using soft mounted file systems may incur unexpected I/O
errors.
To improve NFS read performance, files and file attributes are cached. File modification times get
updated whenever a write occurs. However, file access times may be temporarily out-of-date until
the cache gets refreshed. The attribute cache retains file attributes on the client. Attributes for a
file are assigned a time to be flushed. If the file is modified before the flush time, then the flush time
is extended by the time since the last modification (under the assumption that files that changed
recently are likely to change soon). There is a minimum and maximum flush time extension for reg-
ular files and for directories. Setting
actimeo=n sets flush time to n seconds for both regular files
and directories.
EXAMPLES
To mount an NFS file system:
mount serv:/usr/src /usr/src
To mount an NFS file system readonly with no suid privileges:
mount -r -o nosuid serv:/usr/src /usr/src
To mount an NFS file system over Version 3:
mount -o vers=3 serv:/usr/src /usr/src
To unmount all file systems imported from a given host, enter the following command as root:
umount -h mysystem.home.work.com -a
The hostname must match what is in /etc/mnttab exactly (as shown by the bdf command). For
example, if bdf shows:
mysystem:/projects,
the
umount command would be
umount -h mysystem -a.
FILES
/etc/mnttab table of mounted file systems.
/etc/fstab list of default parameters for each file system.
SEE ALSO
quota(1), fsclean(1M), mount(1M), quotaon(1M), mount(2), fstab(4), mnttab(4), fs_wrapper(5), quota(5).
Section 1M−−472 Hewlett-Packard Company − 3 − HP-UX 11i Version 2: September 2004