Hallo @all
I'm facing poor performance with VxFS ( EMC LUNs, host-based-mirrored volume with logplex ):
We compress and uncompress a 10GB file and here are the results:
pri620[root]/database/sybase_backup {NSH}: time compress test_a
real 1m43.920s
user 1m8.303s
sys 0m14.824s
pri620[root]/database/sybase_backup {NSH}: time uncompress test_a.Z
real 3m29.777s
user 1m18.035s
sys 0m14.054s
Here the same but with two mirrored local disks and ZFS:
pri620[root]/install {NSH}: time compress test
real 1m29.672s
user 1m14.996s
sys 0m9.424s
pri620[root]/install {NSH}: time uncompress test.Z
real 1m27.838s
user 1m19.017s
sys 0m6.383s
Uncompressing is much faster!
When I create the 10GB file with mkfile I can see with iostat that
write performance is about 180-200 MB/s, but uncompressing
the file write performance is only about 55MB/s.
Hardware Oracle T5-2, server instance is a "Logical Domain"
I've read several documentation but I'm not able to get it faster on VxFS.
The only way it was faster is a special mount option:
mount -F vxfs -o tmplog,convosync=delay,mincache=tmpcache
But this seems to be very unsafe.
Any hints?
Regards,
Heinz
