Replace 146GB disks with 300GB disks on EVA6000

[Tapani Reijonen]

I have EVA6000 loaded with 112 disks (full, one Disk Group) and would like to add capacity replacing 146GB disks with 300GB disks. I know that the procedure goes something like this:

1. Ungroup one 146GB disk and wait until it is shown in the Ungrouped disks

At this point the Disk Group starts levelling. Do I have to wait until it is done before continuing to next steps (takes a long, long time)?

2. Remove the ungrouped disk from the bay
3. Plug new 300GB disk to bay and wait until it is seen in the Ungrouped disks
4. Group the disk to the Disk Group

I guess that this is also the point where Disk Group starts levelling. Do I have to wait until it is done?

5. Start all over again from step 1

So basically I'm asking if it is safe to group/ungroup disks from Disk Group while it is levelling if I group/ungroup only one disk at the time and wait for each group/ungroup to finish before continuing with another group/ungroup operation.

[IBaltay]

Hi,
1. yes you should always wait for the ungroup, because it means that data is moving away from the this particular physical disks

4. no you dont need to wait for the leveling finish and you can continue to ungroup

yes it is safe

but your idea is not the best practice according to the performance but only best practice according to the costs:

(Best practices for the newer EVA versions but the main principles has remained the same)

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01677916&cc=us&dlc=en&lc=en&jumpid=reg_R1002_USEN

[Tapani Reijonen]

I looked at the best practices document and if I understood it right, it says that it would be better to create new Disk Group for the new bigger disks and move existing data to new disks. The document also said that I should add all new bigger sized disks at once. The problem is that my EVA6000 has already maximum number of disks installed and they all are on one Disk Group. There is about 3TB available storage capacity according to CV EVA. It is already mixed environment with 300GB disks and 146GB disks. At this point I want to replace 16 146GB 10K disks with 300GB 15K disks. What procedure would you recommend?

[IBaltay]

then the best seems to be ungroup 8x146, then replace them 1 disk at a time with waiting for the disk initialization and then group the first new 8 disks and then do the same with the second group of the 8 new disks (8 physical disks is the RSS default). At the end if everyting goes as it should there will be 2 new RSSes of 8 physical disks in each.

[Michael Leu]

If you have enough free space you can ungroup 8 disks in parallel in the background.

The way I did it last time on a EVA6000:
1) in the evening ungroup in background 8 disk, one in each shelf, for example all from slot 14.
2) next morning remove each disk from the bay (some excercise for walking 8 times between CV GUI and the array ;-)
3) plug in the new disks, with about 1 minute interval between
4) group all 8 disks at once
5) let it level a few percent
6) start to ungroup another column of 8 disks

Hope it helps. :-)