Defrag /usr

[Brett Alan Logan]

Hi,

Tivoli our monitoring tool reported that /usr is fragmented. Is there a tool that comes with HP-UX that will defrag an FS? I don't think there is. If not is there a freeware tool someone could recommend?

I did a dfrag a few years ago and I don't remember what commands I used. I do remember it hosed the FS. What are the risks to defraging?

System Info
HP-UX 11.11
L2000

# grep /usr /etc/fstab
/dev/vg00/lvol7 /usr vxfs delaylog 0 2

# bdf /usr
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol7 1245184 1090632 154552 88% /usr

The system hasn't been patched in two years.

[Jeff_Traigle]

fsadm has a defrag (reorganize extents) option (-e) and a directory reorganization option (-d). The -E option gives an extent fragmentation report. I think these are only activated if you have OnlineJFS.

[john kingsley]

If you have online JFS, you can use the fsadm command:

fsadm -d -D -e -E /usr

[Brett Alan Logan]

No unfortunately there's no online JFS.

Are there other ways to defrag?

[A. Clay Stephenson · Accepted solution]

No. You could backup the filesystem, umount it, run newfs, and restore. Regardless of what Tivoli reports, in almost all cases the performance gains from defragging a vxfs filesystem are difficult to measure much less actually perceive. However, get yourself a baseball and hit yourself over the head because no production HP-UX system should be without OnlineJFS.

[john kingsley]

The only other way that I'm aware of it to backup and restore the filesystem.

It seems odd that /usr has become fragmented though. It should be a fairly static filesystem.

Even without Online JFS, you should still be able to generate the fragmentation reports by running:
fsadm -D -E /usr

[Brett Alan Logan]

Ok thanks for the info. I think I'll pass on the defrag. It isn't worth the time now that I know what is involved.

Online JFS would be nice to have. If I had built the system it would have it.

[Brett Alan Logan]

Solution found