12H Poor Performance on new LUN

[Joshua Scott]

This guy had a similar problem:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=9759

on the other hand, Perhaps you should break the newest lun into 2 luns and set them up so they are accessed through different HBAs.

I could just be a bandwidth problem.

[Ted Ellis_2]

on the server side, I have one LUN I/O going across one adapter and the other 2 going across the other, so there is some I/O balance from the host. I am confident that is not an issue for this....

[A. Clay Stephenson · Accepted solution]

You crossed the threshhold for full RAID 1/0 (although not by a huge amount) but a 2nd problem is that you created 1 LUN rather than 2. I assume that this is HP-UX. You should have created 2 LUN's of equal size. LUNa's primary SCSI path should be thru Controller X (alternate Y) and LUNb's should be exactly the opposite. You then add both of these to a Volume Group and stripe all LVOL's across both LUN's in 64K chunks. When you do this, both external SCSI paths are fully utilized as well as all four internal SCSI buses.

[Ted Ellis_2]

thanks Clay.. I found a similar thread where you covered the same ground... agree, that was not wise on our part. If we get a chance we will drop the LUN and rebuild it per recommendation.... thanks