MSA 2040 + 2050 Question

[RyanBattler]

Hello, everyone!

I have not encountered HP SAN systems before. Therefore, my questions may seem silly. I apologize in advance for this.

We have an MSA 2040 with 12 HDDs of 4TB each. Six of them are in Virtual Pool A in Raid 5 and the remaining six are in Virtual Pool B also in Raid 5. They are mapped and function as two separate volumes.

And now we have an MSA 2050 with 24 HDDs of 1.2TB each. And I want to connect the MSA 2050 to the already configured MSA 2040 mentioned above.

I have connected the hardware and in the web interface of the MSA 2040 I can now see the drives from the MSA 2050.

Now what I want to do: 

I want to build a RAID6 with two drives for HotSpare on those 24 HDDs from the MSA 2050 and make a separate Volume out of that.  Already existing data on the MSA 2040 must be preserved, no data loss is acceptable.

What I am afraid of: 

To build RAID6 I must first select Pool (A or B) and name the new disk group. Won't this action delete the data from the already existing Pool A and B disk groups?  Do I understand correctly that these Pools are just an abstraction for easy grouping of disk groups? I don't want to build Raid 6 and thereby accidentally destroy all data.

And one more thing. Will HotSpare drives affect existing raid5 disk group? I want two HotSpare drives to serve raid6 disk group only. Is this possible? 

[sudhirsingh · Accepted solution]

Hi,

1.You can create multiple disk groups in each POOL, (best practice is to maintain a balance across both POOLs)

2.Creating new Disk-Group in a Pool A/B will not delete existing disk groups.

3.If you have already added drives into a POOL please do not remove them, since missing diskgroup will cause pool to go offline and as a result all the volumes will be inaccessible which belongs to that POOL.

4.Your Raid5 is built on 4TB drives and Raid6 on 1.2 TB drives so Global spare of 1.2 TB drives will support failure of a 1.2TB drive only, It has no impact on Raid5 disk group  which are built on 4TB drives. 

5.Yes, you can have multiple Global spares