Kernel memory fragmentation vs VxFS

[Daniel Proulx]

A problem was found with Veritas filesystem on Solaris systems as can be seen at the following URL: http://seer.support.veritas.com/tnotes/FILESYSTEM/198200.htm
A performance degradation occurs on systems with large memory under some circumstances because of kernel memory fragmentation. I was wondering if HP-UX (10.20 or 11.0) could suffer from a similar problem when JFS (vxfs filesystems) is used. We are running 8 K460/4way servers with 2GB RAM under HP-UX 10.20 with lots of vxfs filesystems. Each server is managing up to 200 GB disk space.

Daniel.

[James R. Ferguson]

Daniel:

I don't know how this might/might not relate to HP-UX. With 11.x there are two new kernel parameters for tuning VxFS's inode cache. Perhaps you will find document #KBRC00002354 of interest, now or later.

There is also an 11.x critical patch available -- PHKL_22121 (s700_800 11.00 JFS 3.3 I/O cumulative Patch) which you may want to look at.

...JRF...