VA7410 slowly?

[alin_5]

I think my storage (VA7410 with 10 HDD 73GB) is slowly. I created a 2GB file (I named this file junk)usig this command:


timex dd if=/dev/zero/ of=/appl/junk bs=1024k count=2000

and the result is:

[appsora]:/ #timex dd if=/dev/zero/ of=/usr/tmp/junk bs=1024k count=2000
2000+0 records in
2000+0 records out

real 4:17.79
user 0.03
sys 14.25


Is this corectly? How can I test if my VA is slowly or he run ok?

Thank you

[Brian M Rawlings · Accepted solution]

Alin: you have made a good start, but many factors combine together on disk performance. First, try a different benchmark tool. Here's one that's been suggested, and which can be downloaded for free:

http://www.netapp.com/tech_library/3022.html

It might also be good to try some of the following:

1> Test relative to a known performance standard. Like, your boot disk. Not fast with a big stripe set, just a disk. Create the 2GB file like you did before, on a convenient lvol on your boot disk (if you have the space). Use the timex command like you did before, and compare with the time on the VA7410. Or use the benchmark tool mentioned earlier on both of them.

2> If the times are roughly equal, your bottleneck is elsewhere in the system. CPU, memory, PCI slots... lots of possible culprits. If the VA results are 2x to 4x slower than your boot disk results, you probably need to make some changes on your VA to speed it up... like, maybe add more drives. Like the Autoraid 12H before it, the VA arrays perform better the more disks you give them, provided that you set them up right.

Search through these forums for VA performance tuning tips -- there are a lot of posts with clues to help you. Here are a few tips to get you started.

1> HP-UX patches -- there are LVM patches (2002 patch bundle? maybe newer?) to improve LVM performance.
2> VA firmware -- you should be on 15 or later, there are several performance fixes in newer firmware.
3> Set the redundancy mode to "performance". The risk of data loss is only slightly higher (still infintisimal), but the performance of the VA will go up.
4> Make sure your I/Os are more or less equally divided between LUNs, using two different I/O paths that alternate which path is primary for each LUN.
5> Adjust your queue_depth kernel parameter to a higher figure than the default of 8. You may have to set this with a script at start-up -- I seem to recall that HP-UX 11 always reset the depth back to 8 on a reboot. You can make a script to run at whatever run level makes sense, and put it into /sbin/init.d, with a link in the rc directory for your desired run level.

Hope this helps. --bmr