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XP24 with External Storage EVA8K performance problems

name_27
Advisor

XP24 with External Storage EVA8K performance problems

I have multiple host connected and few of them are really slow disk i/o (0,3MB/sec). With similar configurations some are not (30MB/sec).
Path parameters and CLPR are set ok.
EVA LUNs are presented failover/failback
I'm wondering about 8 paths to EVA causing this?
EVACtrl-A -> XP
500...48 CL3-E
500...49 CL4-E
500...4A CL3-E
500...4B CL4-E
EVACtrl-B -> XP
500...4C CL3-E
500...4D CL4-E
500...4E CL3-E
500...4F CL4-E

XP priority:
1 500...48 CL3-E
2 500...4A CL3-E
3 500...4C CL3-E
4 500...4E CL3-E
5 500...4D CL4-E
6 500...4B CL4-E
7 500...4D CL4-E
8 500...4F CL4-E

Any advice?
Thanks,
-T-
5 REPLIES
krusty
Honored Contributor

Re: XP24 with External Storage EVA8K performance problems

Hi "T",

First, HP has a handy White Paper about External Storage on the XP: http://h71028.www7.hp.com/ERC/downloads/4AA0-6162ENW.pdf

Next, you may want to look at utilizing additional ports on the XP. Currently you are running all 8 EVA fabric ports thru 2 ports on the XP. Those ports -may- be saturated. Typically you should spread the load a little more. Note on the XP, the different CHA ports can share microprocessors. For example, CL3-E uses the same MP as CL7-E. Likewise, CL4-E and CL8-E share MP's. See if the "buddy" ports are being used also.

You really need a detailed analysis of the layout, but maybe this would help.

Cheers,

Curt
"In Vino Veritas"
IBaltay
Honored Contributor

Re: XP24 with External Storage EVA8K performance problems

Hi,
you can also monitor the CHIP load via the PAXP (Performance Advisor)
the pain is one part of the reality
IBaltay
Honored Contributor

Re: XP24 with External Storage EVA8K performance problems

Hi,
here are some of the key ES recommendations:

a) ES XP Cache mode - cache disabled
b) put ES XP in a separate CLPR
c) up to 4 ES XP links to the same AA EVA
d) at least 2 XP links per EVA for HA reasons
...
the pain is one part of the reality
Matthew Secaur
Occasional Visitor

Re: XP24 with External Storage EVA8K performance problems

IBaltay,
I am in a similar situation as the original poster (except that our XP -> EVA8000 is using 8 XP ports). You said:

"here are some of the key ES recommendations:

a) ES XP Cache mode - cache disabled
b) put ES XP in a separate CLPR
c) up to 4 ES XP links to the same AA EVA
d) at least 2 XP links per EVA for HA reasons"

I understand all of them except letter "c)". Why only 4 links? If you look at the original poster's "XP priority" table, I have that same config times 8 (That is, 8 path groups of 8 paths, each using a different "primary" path). Is this too many? Could this be the source of my performance problems?
You can lead a horse to water, but you can't teach him to fish.
IBaltay
Honored Contributor

Re: XP24 with External Storage EVA8K performance problems

Hi,
because in EVA it is always only 1 controller in the role of the managing controller, that means only 4 FPs from 8 is directly accessing the EVA disk subsystem (especialy reads), the other 4 of the second controller - proxy are accessing the disk subsystem only via the mirror port channels between the 2 controllers which is not optimum and could become the performance bottleneck.
the pain is one part of the reality