Start a Conversation

This post is more than 5 years old

Solved!

Go to Solution

611

March 3rd, 2009 11:00

PowerPath LoadBalancing

Hi,

we have a cx4-120 box, SPA conected to FCSwitch1 & FCSwitch2 and SPB connected to FCSwitch1 & FCSwitch2, the host is connected to the FCSwitch1 & FCSwitch2 with 2 HBA's, so we have 4 paths:
hdisk2 Available 05-08-02 EMC CLARiiON FCP RAID 5 Disk
hdisk3 Available 05-08-02 EMC CLARiiON FCP RAID 5 Disk
hdisk4 Available 0C-08-02 EMC CLARiiON FCP RAID 5 Disk
hdisk5 Available 0C-08-02 EMC CLARiiON FCP RAID 5 Disk
hdiskpower0 Available 0C-08-02 PowerPath Device

When there is write activities on hdiskpower0 volume we figure out that only 2 paths are used:

0 fscsi0 hdisk2 SP A3 active alive 16 0
0 fscsi0 hdisk3 SP B3 active alive 0 0
1 fscsi1 hdisk4 SP A2 active alive 25 0
1 fscsi1 hdisk5 SP B2 active alive 0 0

My question is:
Is this normal because Clariion has an Active-Pasive configuration ?
For a Symetrix box, powerpath will use all 4 paths ?

Thank you for any suggestion !
Dan

9 Legend

 • 

20.4K Posts

March 3rd, 2009 11:00

you got it. A LUN on Clariion is owned by SPA or by SPB so that's why you only see 2 paths working ..both to SPA.

4 Posts

March 3rd, 2009 12:00

DanM - you can set up a poor mans load balance trick. The following info is from a Client lpar that is getting its disks thru 2 vio servers, each vio server has 2 HBAs, feeding back to 2 switches and on CX500. All we are really doing is spreading the load across the VIO hba's and efectivly (sp) spreading across the 2 SPs.
*** please test - I have this config, (# of paths vary), set up on 6 lpars - NMON shows a pretty good spread at the vio level.

Do something like this on the client lpars;
338 chpath -l hdisk0 -p vscsi1 -a priority=10
339 chpath -l hdisk1 -p vscsi0 -a priority=10
340 chpath -l hdisk2 -p vscsi1 -a priority=10
341 chpath -l hdisk3 -p vscsi0 -a priority=10
342 chpath -l hdisk4 -p vscsi1 -a priority=10
343 chpath -l hdisk5 -p vscsi0 -a priority=10
344 chpath -l hdisk6 -p vscsi1 -a priority=10
345 chpath -l hdisk7 -p vscsi0 -a priority=10
346 chpath -l hdisk8 -p vscsi1 -a priority=10
347 chpath -l hdisk9 -p vscsi0 -a priority=10
348 chpath -l hdisk10 -p vscsi1 -a priority=10
No Events found!

Top