topic MSA1050 - Delete Disk Group in MSA Storage

MSA1050 - Delete Disk Group

_Paolo — Mon, 10 Aug 2020 22:39:27 GMT

Hi,

I have a MSA 1050 with VE100R002 firmware configured as below:
- Pool A -> DiskGroup1 -> 4 x 300GB 10K SAS RAID5
- Pool A -> DiskGroup2 -> 3 x 300GB 10K SAS RAID5
- Global Spare -> 1 x 300GB 10K SAS

There are 4 LUNs exposed to the hosts.

I want to make a backup of the data and delete 3 LUNs, coming to occupy only 500GB. At this point, could I delete the DiskGroup2?
Do I risk losing the data on the remaining 500GB?
I would like to delete DiskGroup2 in order to recreate a new Virtual Disk Group with 9 disks in RAID5.

Thank you a lot
Paolo

Re: MSA1050 - Delete Disk Group

SUBHAJIT KHANBARMAN_1 — Tue, 29 Jun 2021 04:18:56 GMT

@_Paolo

First check how much space used or consumed by DiskGroup2. Also you need to check how much space is free for DiskGroup1 because when you delete DiskGroup2 then all data will migrate from DiskGroup2 to DiskGroup1. This process is called VDG drain. So run command "show disk-groups" to check how much shows as "Size" which is nothing but total size of the VDG and also see "Free" which is nothing but shows how much space free in that VDG. From that you can calculate how much is used or consumed.

Also keep in mind, for optimal performance:
All virtual disk groups (VDGs) in the same tier should have the same RAID level, capacity disks, and physical number of disks.

Hope this helps!
Regards
Subhajit

I am an HPE employee

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Re: MSA1050 - Delete Disk Group

_Paolo — Wed, 12 Aug 2020 23:04:33 GMT

Thanks for the reply.
With a total of 13 disks I cannot create VDGs with the same number of disks even if I use the same RAID level. I don't have the license that enables tiering.
How does MSA deal with two VDGs with the same RAID level but different number of disks?
For example: DiskGroup1 with 4 disks in RAID5 and DiskGroup2 with 9 disks in RAID5? Will DiskGroup2's IOPS levels be capped down to match DiskGroup1's performance?
Thank you