Device busy

[Praveen Bezawada]

Hi
We have two database servers which are using the same kind of DiskArray. But on one we use veritas volume manager and on another we Solaris volume manager. At about the same load, the disk busy on server using solaris volume manager is over 50% whereas for veritas it's only 20%. We are using the command sar -d and iostat -x to monitor. We have Raid1 on both the disk arrays.
Does this means that performance of Solaris volume manager is bad? Or is there any other aspect we need to check before making conclusion?

Br
...BPK...

[Ivan Ferreira]

I think that you cannot get to that conclusion unless you:

- Run exactly the same performance tests on both servers. Server hardware and workload will impact the performance, they should be mostly equivalent (memory, bus and cpu configuration). You said that they have more or less the same workload, this is not good enough.

- You could try with an offline test (stopping all services and writing something to disk), and monitor your disks performance. This could give you a little more fair results, but you should consider that the file system buffers/cache (besides the hardware) can affect your tests results.