Hi

I m using Zabbix to monitor that server, and I receive that message, what is the best way to free the space in that file .

Here are my server disk usages.

#df -h
Filesystem Size Used Avail Use% Mounted on

10.10.2.24 :/file1/file2
453M 341M 85M 81% /z/x/y

It depends a lot on what is in filesystem, /z/x/y.

You could go to /z/x/y then run "du -sk * |sort" so it gives you sorted output by size to see what is taking up the most space. If you see subdirectories you could run that within the largest to see what within each is taking up space.

If the filesystem is under /home you might use that to identify largest users and tell them to clean up their own files.

if the filesystem is /tmp or /var/tmp you might be able to remove the oldest files you see there. Before removing a file run lsof against it to be sure it is not currently in use.

If the filesystem is something else you'd need to determine what is safe to remove. Many applications create temporary files and/or logfiles under their own directory structure so it is often safe to remove older files of those types. Failing that, you sometimes need to stop the application, truncate the log, then restart the application.

DO NOT DELETE FILES (EVEN LOGS) IF THEY ARE IN USE AS SHOWN BY LSOF.
When you delete an "open" file it doesn't really go away - only the name does - the inode is still using as much space as it did before the deletion and the only way to reclaim the space is to stop the application that was holding the file open.