SAN boot Linux with MPIO

[DurangoCase]

Has anyone had success with SAN booting using MPIO? I am able to SAN boot with a Dell/Q logic/Brocade/EMC solution Running CentOS 5.2. I have configured DM. I am not able to MPIO yet. Does anyone know if it is possible to pull this off?

 

[SANEngInCO]

When you boot from SAN, you are only pulling the LUN down a single path. There is no multipathing at the BIOS level to help with failover. So if that path fails, the LUN goes away. I've read people saying that once the OS is up you can multipath, but I've never seen that actually implemented successfully. This is the major drawback for BfS and the reason I would never suggest it. You don't gain any performance in the OS doing that and you add a SPoF into the environment.
That's just my $0.02.

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"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
Albert Einstein

 

[SANEngInCO]

I should have included my experience in my previous post.

BfS - EMC CX700 through Cisco MDS9509's to IBM HS blade centers.

We were working with EMC support to make some changes and when it "accidentally" failed over from one controller to the other, I lost an entire blade center since it's one path was gone. We used PowerPath in the OS, but like I said it doesn't help in this case. It helps with the data LUN that is down two paths, but not BfS.

We removed all BfS from our environment and went back to internal disks for OS as we gained next to nothing in performance. We had to redo 7 blade centers with this change.

Good times.

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"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
Albert Einstein

 

[DurangoCase]

Well, it works great. Multipathing in bios and multipathing in the OS. I can fail either path at any point in POST or OS and it fails over. fail back is instant. Load balancing is round-robbin. SAN boot with MPIO works in CentOS 5.2 out of the box.

 

[kewitz]

burangocase is right. works perfect also with native driver of suse linux and also with centos 5.2.

 

[DurangoCase]

Kewitz,
Happy it worked for you. What is your hardware combo?