Comment 18 for bug 1100843

C Cormier (ccormier) wrote :

@serge-hallyn
I'm using Netapp filer in c-mode for NFS storage, mount options are: (rw,nosuid,nodev,noatime,hard,nfsvers=3,tcp,intr,rsize=32768,wsize=32768,addr=x.x.x.x).

However, I can reproduce this on a a host with or without NFS, using local disk, qcow2, or raw images and the OP was using FC SAN.

I've tried to reproduce your success by buiding a new VM the latest preciese 12.04.02 with updates, but i have been unsuccessful. It happens immediately after the restore 100% of the time.

The quickest test i've found is this, it helps aid in your reproduction as it's an immediate indication.
-Get/Compile lmbench
-build it
-run
# touch tmpfile
# for i in null read write open ; do sleep 1; ./lat_syscall -N 1 $i tmpfile; done
- the latencies for read/write generally increase up to 2x, and the open/close by about 30% post restore.