Upgrading HDDs for additional capacity?

[bcourtney82]

I understand that if I need more cache, I can upgrade the size of the SSDs I'm using in my shelf. But if I want to increase the amount of available capacity for the array, I need to purchase an expansion shelf, even though there are multiple drive sizes supported by the different controller models. Is there a technical reason why one can't upgrade the HDD's in the same way you would the SSD cache, or is this a business-imposed limitation?

[Nick_Dyer · Accepted solution]

Hi Bill,

it's simply to do with RAID. if you were to attempt to swap out a drive (say 2TB) for a bigger drive (say 4TB), the RAID rebuild can only build for the rest of the capacity drives in the RAID set... meaning that your new 4TB drive would only be able to address 2TB of space of the disk, as the rest of the drives within the RAID set are 2TB drives. This would also cause a lot of complexity, potential performance issues (rebuilding 12 disks one at a time could take a long, long time) and support problems... so it's safer, cheaper and easier to add an expansion shelf.

[Russell Mellon]

Resurrecting an old thread. But what if, hypothetically on a Nimble CS220, I don't care about the existing data on the array and I just replace all the drives on the shelf at the same time?  Is there a controller or software limitation on the maximum drive size?

[Sunitha_Mod]

Hello @Russell Mellon, 

Thank you for writing to us! Since you have posted in an old topic and there is no response yet, I would recommend you to create a new topic using the create "New Discussion" button, so the experts can check and assist you further.