Add more cache SSDs to an existing Nimble array

[CadenLange]

What are the rules for adding more cache SSDs to a Nimble HF4o array?

The Nimble array consists of the controller shelf and two expansion shelves. All the A sleds are populated in all shelves and the B sleds are all empty.

If I have a set of three new cache SSDs does it matter where these go?

Should all three go in the B sleds of the controller shelf or perhaps I populate 1 B sled in each shelf - or does the Nimble just treat it all as a single cache pool and it doesn't really matter where they go? I couldn't see any guidance on the locality of the SSDs when upgrading the cache just statements saying to populate all A positions before moving onto the B positions.

many thanks

[support_s]

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[Sheldon Smith]

Hello,

In the InfoSight Nimble Documentation, look in the Hardware Guides. There are several Cache Upgrade docs dependent on the particular array hardware model.
All three should go in the controller shelf's Drive B sleds. Once the controller cache drives sleds are all populated, the next set of three would go to an expansion shelf.

[CadenLange]

Many thanks
If they’ve been put in different locations (I think they may have been populated 1 per shelf) is it just a case of moving them? I guess we can leave 24hrs between moving each one but don’t think that would be necessary for us.
Thanks again

[Sheldon Smith · Accepted solution]

Yes. Nothing is stored on them. All volumes reside on the HDDs.

The "24 hours" is for the general case with a busy system with all cache slots filled and in need of more cache. Change them one at a time and give them 24 hours to 'heat back up'.

You can use the Nimble GUI Performance Real-Time displays to see what latency and cache hits look like when you move a single cache drive. If there are noticable changes in either, wait until they get back to a level state. Then move another.

Finally: If the Hardware page is showing the right amount of cache for the number of drives you have, it doesn't matter. I haven't looked at a customer's system with cache drives spread out like yours.

[CadenLange]

Thanks Sheldon

I checked the hardware guides and cache upgrade guides in infosight and they don't specifcally specify the need to add the new cache SSD's into the B-sleds in any particular order...... just to make sure the A sleds are first fully populated.

I'll check the total cache capacity against what I'm expecting to see (having added the new disks) and make sure everything is working as expected.

Thanks for you help.

[PattyK]

One SSD drive in Nimble HF40 failed. Now I can not find HPE part for SSD in Nimble HF40. it looks like that I musy buy MA only. Could I purchase only SSD from Sumsung and change it into the old disk bay then reinsert to Nimble HF40 (The brand is Sumsung)?

SAMSUNG MZ7LM960HMJP-00005 PM863A 960gb SATA 6Gbps 2.5Inch Ssd

[Vinky_99]

@PattyK 

Good day! 

Replacing a failed SSD in a Nimble storage array with a non-HPE branded SSD is not recommended and could potentially lead to issues with the array's performance, stability, and support coverage. Nimble storage arrays are designed to work with specific HPE-branded components, including SSDs, to ensure compatibility and reliability. Using non-HPE SSDs may void your support agreement and could lead to data breakage or other problems.

Hope this is clear!