EVA4000 and wrong Read performance

[Andreag_77]

Hi,
in a SAN environment with EVA4000 i have found problem for I/O performance on Library Backup from SAN storage. I have done some test, the library is ok (100Mb/s) but with PAT ReadData utility the read performance on storage is very wrong (about 20Mb/s on every LUN mapped on servers).
The Fault T. is Raid 5, this is the best solution for read performance..
someone can give me some info for troubleshooting this problem??

thanks very much
Andrea

[leif halvarsson]

Hi,

Sorry for the late response but I do not regulary monitor this forum.

I had a similar problem but in my case, the disk system was an EVA3000.

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=971067

At last, I found a possibly source of the problem. The disk system with bad performance had very little free capacity (about 5%).

- How much free capacity do you have ?
- Is it possible to free up some space ?

If yes, create a test LUN, use the PAT tool to test performance.

Then, free up some space, test performance again, using the same LUN.

Next, delete and recreate the LUN again. Do a new performance test.

Do you notice any difference ?