Best way to config SAN in Linux

aLuViAn · 01-27-2013, 06:28 AM

Hi,

I know this is a repeated question here, but I really need to find a good solution for that.
We have a couple of HP ProLiant Servers with RHEL 5.4 installed on them and Two SANs, One is HP P2000 and the other one is EMC VAX.
They are connected to the Servers using QLogic Fibre Switches.
I have tried using Multipath for SAN connection, but due to some unknown issue (I don't want to give you a headache, it just took 2 weeks of me & my supervisor's precious time to dig the problem and at last, it did not work!) multipath seems to be very unreliable for our servers.
We also have some of LUNs partitioned and used for Oracle DataBase, Oracle (fortunately) uses its own File System and we had no issue up to now (for about three months)
Can you suggest a reliable method of connecting SAN to Servers? Note that I cannot reboot some of the servers and I need this SAN mapping for backup area.

TB0ne · 01-27-2013, 11:00 AM

Quote:

Originally Posted by aLuViAn

Hi,
I know this is a repeated question here, but I really need to find a good solution for that.
We have a couple of HP ProLiant Servers with RHEL 5.4 installed on them and Two SANs, One is HP P2000 and the other one is EMC VAX.
They are connected to the Servers using QLogic Fibre Switches.
I have tried using Multipath for SAN connection, but due to some unknown issue (I don't want to give you a headache, it just took 2 weeks of me & my supervisor's precious time to dig the problem and at last, it did not work!) multipath seems to be very unreliable for our servers.
We also have some of LUNs partitioned and used for Oracle DataBase, Oracle (fortunately) uses its own File System and we had no issue up to now (for about three months)
Can you suggest a reliable method of connecting SAN to Servers? Note that I cannot reboot some of the servers and I need this SAN mapping for backup area.

I don't want to sound like I'm brushing you off, but you're in a 100% supported, certified environment. EMC, HP, and Red Hat support should all be involved in this, if you're having that many issues.

I've never had a problem with multipath with EMC SAN's, and I can't imagine that HP is THAT different (note: never touched an HP SAN). One thing that DOES make a difference though, is the Qlogic drivers. Did you get them from EMC? They have drivers, and the 'generic' QLogic drivers have been reported to have some issues. Again, I've only ever used the ones from EMC, so I can't speak to it directly. Also, have you tried using something like EMC's PowerPath for multipathing, instead of what's in RHEL?

Also, I know you're probably aware that RHEL 5.4 is a bit aged at this point...do you have the current patches/updates in place, and have you considered running a test with another current RHEL machine, to see if that alleviates the problem?

MensaWater · 02-16-2013, 09:14 AM

A couple of good links from RedHat for SAN configuration:

RHEL5:
https://access.redhat.com/knowledge/...ide/index.html

RHEL6:
https://access.redhat.com/knowledge/...ide/index.html

We use multipath in our environment for Hitachi VSP disk array and don't see issues with multipath itself.