Advice on adding more disk to MSA 2052

[adamdb_uk]

Hi,
just wanting to confirm some potential expansion plans for adding addtional storage to an MSA2052 system. Currently the MSA has 2 virtual pools A and B.

Pool A contains the following

Slots 1-4 / 4x1.6tb ssd (raid 5)
Slots 11-14 / 4x1.8tb sas (raid 5)

Pool B contains the following
 
Slots 5-8 / 4x1.6tb ssd (raid 5)
Slots 15-18 / 4x1.8tb sas (raid 5)

There is also a hot spare SAS drive in slot 19 for the 1.8tb drives
There are also two unused 800GB SSD drives in slot 9 and 10. (believe these ship with the bare system but have never been used).

Customer needs to expand useable space due to growth. As cost is an issue the plan is the following.

1. Remove the 800gb SSD drives. (slots 9 and 10)
2. Move hot spare from slot 19 to slot 10. (assume we just need to unmark the drive as a spare in the gui first and then mark it again once moved).
3. Add a NEW 1.6tb ssd hot spare into slot 9 (vacated in step 1).
4. Create two new disk groups the empty slots from 19-24

3x1.6tb SSD / Raid 5 (slots 19-21)
3x1.8tb SAS / Raid 5 (slots 22-24)

Add these two new groups to either pool A or B to extend the available storage.

Whilst I appreciate these are 2+1 rather than 3+1 raid this seems like the best compromise to give the customer more space without adding enclosures.

Can you advise if there are any issues with doing this other than a potential difference in performance between them (more likely I guess for the SAS tier).

Currently all the volumes are set for performance mode anyway meaning the majority of hot data is kept on SSD.

Any advice or issues you can see please let me know.

( did actually ask this question via support but after 11 days there's still no response hence posting here)

thanks
Adam

[SUBHAJIT KHANBARMAN_1 · Accepted solution]

@adamdb_uk 

Plan looks fine to me as you are aware of little Performance impact due to imbalance of drives in same tier VDGs.

Only thing I want to mention that there is no need to unmark SAS drive at slot 19 and remark at Slot 10. You can simply move the drive from Slot 19 to Slot 10. It's about drive metadata where the information already written and the drive knows that it's purpose is to be used as spare drive.

Final will be,

Slots 1-4 / 4x1.6tb ssd (raid 5)
Slots 11-14 / 4x1.8tb sas (raid 5)

Slots 5-8 / 4x1.6tb ssd (raid 5)
Slots 15-18 / 4x1.8tb sas (raid 5)

Slot 9 1.6tb ssd (Global Spare)
Slot 10 1.8tb sas (Global Spare)

Slots 19-21 / 3x1.6tb SSD (Raid 5)
Slots 22-24 / 3x1.8tb SAS (Raid 5)

Hope this helps!
Regards
Subhajit

I am an HPE employee

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[SUBHAJIT KHANBARMAN_1]

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Hope this helps!
Regards
Subhajit

I am an HPE employee

If you feel this was helpful please click the KUDOS! thumb below!

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