Proper Procedure for Moving Disks Within a CLARiiON?

Question

Wondering if anyone knows the proper procedure to move around physical disks within a CLARiiON? Or any procedure really. These would be for disks that already contain data. So, for instance, if I had a 6 disk RAID 5 group and I wanted to move 3 of them to a different DAE how might I accomplish that best? I've swapped disks sizes and speeds before, but it would logically seem to me that a different process would be needed here. Can I just move them and have them recognized? Power down the array and move them? etc. I'm doubting that but I know many servers allow the moving around of drives and can't see why a SAN as powerful as the CLARiiON wouldn't allow it as well but I have been unable to find any documentation towards such a goal...

ruroruro · Accepted Answer

Do you want to do it without breaking RAID?

If I understand your question rightly,
1 you need to back up the data first
2 break the RAID
3 move 3 disks to other DAE.
4 make new RAID and rebind LUN
5 restore data

you cannot move around disk unless breaking RAID

csmykay1 · Answer

I think the ultimate question is:1. Can you afford to buy new disks?If you can then you all you need to do is use the built in LUN migration tool in Navi that start in Flare code release 16. If you are not at LEAST at Flare code relase 16 than I recommend you upgrade.2. If you can not buy new diks?Then I recommend you do what the person in the above comment says to do. You can not move drives around from one DAE to another. If you do your RG will be destroyed.Regards,Shmac

Jeff_Tabian · Answer

I was mostly hoping that somehow there was something I didn't know about the CLARiiON. The customer was disappointed with the answer because their old SAN could do this and so can many of their servers. I have to agree with them since the CX is in its 3rd generation now it would seem like a simple request to be able to just physically rearrange drives (The data is still all there after all). Even if at worst you had to issue a command to update some type of mapping table etc. There should be some way of doing it. It reminds me of when you call MS with an exchange problem and they say "Sure thats easy to fix"

1. Backup your Exchange Data
2. Format Drives
3. Reinstall OS
4. Reinstall Exchange
5. Restore Data

As for buying additional drives its more a factor of how many different flavors there now are. Where the LUN is now is 10K 146 and all the new ones being bought are 15K. It only requires 10K so it needs to stay put just the drives physically have to move to make room for the way the new 15Ks are wished to be installed to keep a 4x5 MetaLUN all together (for simplicity/manageability/etc) well and technically to also preserve it being bound across different backend buses etc. Many reasons it would have been nice if it were easier than it is to accomplish...

csmykay1 · Answer

Ahh I see.

So you have a Meta LUN bound across 2 disk shelves? If that's the case then you are stuck in a bind. However the option with LUN migration is still your best. I know it would cost the customer more money but you have to be able to convince them that this is the best solution for there needs. Also you can still purchase 10K drives

Shmac

Allen Ward · Answer

I guess my first question (which is already partially answered) would be "What are you actually trying to accomplish with this move?" You mentioned making room for new drives, but I'm not clear on why the new drives need to be located where the existing drives are. I'm also not clear on the need to spread the RAID group over two back end loops when you are only dealing with 10K drives (implying that performance isn't the driver).
If you can clarify this, there may be another solution that you haven't considered...