I was just reading about Vicom offering and exchanging information with the NetApp guys here. I strongly agree with you about offline data migration (the only one I run hot is Storage vMotion for vSphere...also for I cas see the VM stay up and running :-)! And the other concept that's is often forgotten regards the reboots needed installing the software for MPIO a/o other stuffs like FC host utilities, Snapdrive and more...If I think i.e. to a Windows system there are at least three reboots (patches, FC utils, MPIO) and, if I want to set i.e. ALUA there's another one after set the policy to RR!

Anyway customer will accept just one stop and for no more than 4 hrs and this could be enough for the switch on the new storage, if everything will go fine.

Regards

-----Messaggio originale----- Da: Kenneth Heal [mailto:kheal@hotmail.com] Inviato: domenica 6 marzo 2011 19:52 A: Milazzo Giacomo; toasters@mathworks.com Oggetto: RE: SAN data migration

Hi Giacomo

A device we sometimes use for these kinds of migrations is the Vicom (http://www.vicom.com/index.htm).%C2%A0 With a Vicom you can do online and offline migration.  That said, you will nonetheless normally need at least one reboot because you have to uninstall the old multipathing software and install the new software.

I tend to be a bit conservative and prefer to do an off-line migration, for the simple fact that if something were to go wrong I could go back to the previous scenario.  Admittedly one is not always afforded this luxury.

Generally after such a change I want to see the host pass a reboot-test anyway to know that if there were ever a power outage everything would come back on-line.

cheers Kenneth

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From: G.Milazzo@sinergy.it To: toasters@mathworks.com Date: Sun, 6 Mar 2011 19:03:16 +0100 Subject: SAN data migration

Hi all,

once upon a time there was “ReplicatorX”…and now? ☺ Anyway I’ve never used it and I don’t know about its pros and cons.

I should plan a SAN data migration from dozens of servers and hundreds of LUNs on HP EVA 5000, IBM DS 4800, EMX CX700 and 300 and so on…

…and all of this has to be performed online, with no disruption, better if agentless (os are Windows, Linux, AIX and more, cluster based on Windows, RHEL, Suse, Oracle…)

Just one restart could be admitted for each systems…

Any suggestion, tools …

Thanks in advance,

On Sun, 6 Mar 2011, Milazzo Giacomo wrote:

Anyway customer will accept just one stop and for no more than 4 hrs and this could be enough for the switch on the new storage, if everything will go fine.

That's a pretty tough requirement, but there are certainly things that can do it. Regardless, I think anything you try to use is going to require some kind of downtime, either to install the MPIO software or to install hardware layers to handle it.

Our current favorite SAN tool is an IBM SVC. Whether it falls within the same pricepoint as software solutions is a question, but it's worth checking out.

The thing works very, very well. It's a SAN virtualization appliance. There's a mode called "image" mode that allows you to take a backend LUN from any storage unit and bring it into the SVC unchanged. One quick outage to remount the filesystem from the SVC instead of the backend storage and you're back up and running.

Once the LUN is in the SVC, online LUN migrations from any backend storage to any other is a piece of cake, and the host OS never notices. It's completely transparent and nondisruptive.

So, you'd have a single quick reboot of any system that requires a LUN migration, and then you're all set to migrate whatever you want. If you keep the SVC in the loop (and it does increase performance of your SAN), you can do future lifecycle management and data migration completely nondisruptively without even the reboot to get onto the SVC.

-Adam