NAME

dmtouch - update last access time for files

SYNOPSIS

dmtouch [-v] files

DESCRIPTION

Updates the "last access time" for each of the given files. This is similar to the command touch -a files, but is intended for use on a DMF filesystem where touch -a does not function as expected.
When the file to be updated is migrated to tape, the command will wait for it to be retrieved before updating it.
This command is intended for use when one or more files are to be used in a later command, and you want to ensure that the files are

a) not migrated

b) not likely to be migrated soon.

By updating the "last access time", you make sure that the file is not "first in line" for migration. This command is typically used before starting programs that will read/update the named files.

OPTIONS

FILES

This command is /noserc/felles/bin/dmtouch

DIAGNOSTICS

Program returns 0 if completed without errors.

If the given filename does not exist, a message is written and the program continues.

BUGS

None known.
Not really a bug, but keep in mind that this command should not be "abused". You are not alone on the filesystem so using this command to keep your files from being migrated only means that someone else's files are being migrated instead. In particular, if everyone starts using this command for all of his/her files the whole idea will fail.

AUTHOR

Arild Burud <noserc@dnmi.no>

EXAMPLE

Updating status for a 1Mb file mpl1 that has been migrated to tape, and measuring elapsed time for the command (note time spent waiting for file to be retrieved from tape):

time dmtouch -v mpl1

will print as follows :

Updating mpl1 ...

real user sys

0m34.392s 0m0.009s 0m0.025s

SEE ALSO

dmattr(1), dmfind(1), dmget(1), dmls(1)