EVA3000 - Migrating 146GB FC disks to 300GB FC disks

[Jo Rose]

Hello,
Our customer has requested that their 3 EVA3000s (each with 2xhsv100 controllers, 4 shelves and the maximum 56x146GB disks) are migrated onto 300GB disks.

Our SAN engineer has recently left the company and so someone else is charged with picking up this work - this is difficult without a written procedure to follow.

I am aware of some of the factors involved, such as the first 2x300GB disks being grabbed by the EVA as part of 'single' disk failure protection, but overall, I wondered if anyone has a written process for performing such a migration.

Unfortunately the customer has elected not to replace the hsv100s with hsv110s, which would have allowed us to scale up to 8 or 12 shelves.

My major worry is how many disks can be swapped simultaneously and how to control the performance impact of levelling - can levelling priority be controlled ?

If anyone has done a full EVA disk migration like this, from experience, how long did it take ? Is it easier to backup the entire EVA , remove all the 146GB disks, put in the larger ones and initialize the EVA ?

Would be interested to hear anyone's experiences on anything related to EVA disk migrations.

Regards
Jo Rose
Technical Architect

[Uwe Zessin]

Leveling on a fully loaded EVA can easily take many hours and, as far as I can tell, there is no 'performance switch'. Obviously you need many leveling operations. Also, disk ungrouping is a serial process. I'd say that you will spend many (elapsed) days with a lot of time waiting for the ungroup/regroup/leveling process to finish.

Don't know if you are exclusively using VRAID-1, but ungroup/regroup can also destroy the parity state of your disk group(s). It can be fixed by swapping physical disk drives.

[Sheldon Smith]

Well first of all, there is no "swapping" of disks. You can Ungroup a physical disk, wait for it to complete, remove it from the shelf, put the replacement in, and finally add it back into the Disk Group. Then repeat the process for the next disk.
I would suggest starting the Ungroup operation, and then stopping by the next day to see if that one is done. Don't worry about leveling. You just want all the data migrated off the original spindle.

Idea. Got a spare EVA3000? Got a friendly Sales Person?

Add a temporary fourth EVA3000 with the desired 300GB drives, replicate all the storage from one of the originals (a perfect scenario for SSSU's Capture Configuration), then use the OS to copy from the original VDisks to the new ones. Update presentations, take down the original 3000. Replace its disks. Repeat the process with the 3000 now being the next target. Finally, one of the original EVA3000s becomes the extra one. I assume this will still take days, but probably not months.

[Jo Rose]

Unfortunately, timescales now prevent me from pursuing HP to see if a loan EVA can be obtained . I have to press ahead with a process which involves:
1) locate 146GB disk
2) ungroup from default disk group - levelling
3) physically remove disk from EVA
4) insert 300GB disk into empty slot
5) add to default disk group - levelling

My questions are:
1) can someone direct me to a manual page which describes use of the locate function in detail ? Couldn't find this in the CommandView EVA user guide ???
2) When ungrouping a disk does levelling automatically occur ?
3) Does levelling have to complete before the disk can be physically removed ?
4) If levelling is continuing and the ungrouped disk has been removed, can the new 300GB disk be inserted ?

Anything else I need to be aware of ?

Thanks all for your help.

Regards
Jo Rose
Technical Architect

[Uwe Zessin · Accepted solution]

1) Just press the button and you will be presented with a new dialogue which is pretty self-explanatory. Please don't forget to turn off the LOCATE before leaving the dialogue. See 3.

2) Yes.

3) You can remove the disk once it no longer belongs to the group - I'd say that is not necessarily related to a leveling. Once the disk is ungrouped, there is also a button on its property page. Press this button and the disk is LOCATED for you.

4) I don't see a reason why not - there will be a short interruption on the back-end loop has part of the plug-in, but that is how it works. You should, however watch the disk if it properly comes up within 60 seconds.