Head swap or moving disk shelves and preserve data?

storage_ergo · ‎2014-01-13

Hi,

I have a customer looking to get from 3040's to 3250's and we are trying to determine the best course of action. They have data on the 3040's that they would like to preserve and move to 3250's We are considering doing head swaps or just moving the old shelves onto the new system. I'd like to get some opinions from everyone here one what they would do. It seems to me that moving shelves would be easier, but I am not entirely sure. The customer does not want to upgrade the existing 3040's Data OnTap which is currently at 8.1.2 so if the new system comes with something higher then that I would have to downgrade it first correct ?

Thoughts ?

HENRYPAN2 · ‎2014-01-13

Hi Storage ERgo,

4 years ago was the last time I choose to swap heads from old FAS6020 to new FAS6280 was duo to the old 6020 got 1,100+ drives on each pair of header.

Choose head swap only need 1 down time & none of my 2 PB production data don't have to be migrated.

NetApp Consulting Service Group got full procedure for the head swap.

Good luck

Henry

billshaffer · ‎2014-01-13

Maybe I'm missing the distinction between a head swap and just moving the shelves between systems? It's the same functional thing, the only difference is whether you pull the old heads and put the new ones in, or put the new ones in a different rack and move all the drive shelves over. My money is on swapping the heads - you avoid having to mess with all the drive shelf cabling.

The new system won't "come" with an OS installed - the OS sits on the disk shelves that you'll swing over. You'll need to change ownership of the drives/import the foreign aggregates from the special boot menu. And I advise checking the eeprom values on the new heads and comparing to the old heads (printenv, setenv from the LOADER prompt).

As Henry said, you should be able to find a good document on the support site. It should be pretty straightforward.

Bill

aborzenkov · ‎2014-01-13

"Head swap" - old vol0 is retained. "Move shelf" - connect shelves to running filer with own vol0. That's how I define it for myself

Head swap is not overly complicated, but still there are subtleties. It makes sense to arrange professional service, especially if one does not gave good experience with NetApp.

billshaffer · ‎2014-01-14

Hmm, okay, I can see that. If moving shelves to a system with its own vol0, you would most likely need to make sure the new system matches the version of the old system. There is probably a small version crossover where it wouldn't matter, but better safe than sorry...

I agree with aborzenkov about professional services. Even if you couldn't buy them with the new heads, you could at the very least sit down with your SE and hammer out the exact process.

Bill

vims · ‎2014-01-14

Hello

We did head swap, described below, 31xx to 3250

https://communities.netapp.com/thread/26840

storage_ergo · ‎2014-01-21

Hi All,

Thanks for the replies. I think I may be over thinking this a little bit. I have boiled my thoughts down to a couple of questions maybe those of you with experience can help me answer.

The way I understand it is that there are two options when replacing controllers, one is to keep the original root volume from the old controllers or use the new root volume from the new controllers. We have elected to keep the original root volume from the old controllers, which are running 8.1.2P4 and for reasons beyond my control the customer cannot upgrade to the next version.

so my questions are as follows:

1. What happens if the new controller comes with DOT newwer then 8.1.2P4, can I downgrade that to 8.1.2P4 and proceed from there ? I know for fact that it will be coming with 8.1.x for sure but more then likely it will not be the same version. The new system will be comin with new shelves so I know there is an OS attached to it, I think during the order process the distributer did not give us a "head swap" option.

2. When it comes time to bringing the data over is it simply a matter of re-assiging the disks to the new system ID and then making the foreign Aggregates online ? IS there anything else to be aware of during the process?

Thanks

Kevin

aborzenkov · ‎2014-01-21

1. Just install version you need using normal procedure. It is possible to switch between minor versions without any issues.

2. There are guides for head swap on NetApp site. But in summary - shut down, connect old shelves (do not connect new at this point), boot in maintenance, destroy mailboxes, reassign disks, reboot in normal mode. Then connect new shelves when online.