Filesystem monitoring guidelines?

[Jimmy Rogers]

Our filesystem monitoring typically alerts us at 95%. However, Oracle DBA's increasingly are wanting to use 99% of a filesystem even though there is free space in other data filesystems. The datafiles are static size and do not grow, but I have concerns about going to 99% Is this still good practice, to keep 5% of a filesystem free? Or is this just a leftover from the HFS days? Doesn't there need to be freespace to write to lost+found in the event of a crash? Any other reasons to keep freespace on an Oracle data filesystem?

[Geoff Wild]

For us, we don't monitor oracle file systems (data files) unless they reach 100% - then we jump on the dba's....

Everything else:

85% Warning
90% Major
95% Critical

Except for things like archive log directories - warning @ 15%, major @ 30% critical @ 50%

That's what we do in OVO.

Rgds...Geoff

[Prashant Zanwar_4]

We have simply excluded oracle file systems from monitoring as it's always tight with those!! And it's DBA's baby, we have been kept ourself limited to space requirment and allocation stuff.
Thanks
Prashant

[John Poff]

Hi,

It used to be that we liked to keep Oracle filesystems from reaching 100% so that we could add some disk space via Online JFS. Once the filesystem is completely full, Online JFS will choke when you try to add more space, and you have to make something go away.

Now, we have large disk arrays and lots of filesystems, so it gets to be more of a shell game where we just create more filesystems and the DBAs move datafiles between filesystems as needed.

JP

[Ray Brewer]

One thing to think about is if your filesystem goes to 100% full and you determine there is nothing that can be removed you will need some free space to extend the file system on the fly using "fsadm". This assumes of course that you are using OnlineJFS. There is also a way of triggering your alerts on the actual MB's of free space instead of percentage. This is the method our Oracle DBA's prefer. Otherwise you could always set up disk quotas to make sure there will always be free space.