Put node root Volumes on three small SSD devices inserted into each controller instead

[RJC]

Hi All, I'm recently confronted by issues relating to providing space for root Volumes.

Root Volumes always go on the same kind of disks that the data goes on. In order to stop wasting space this has given birth to ADP, etc...

Has it ever been contemplated to move the root Volumes to three dedicated and independently removable small SSD devices inside each controller? Aside from the hardware development effort for this are there any downsides?

[AlexDawson · Accepted solution]

Since ONTAP 8.3 for lower end and 9.3 for all systems, a small partition of drives is used for the root aggregate, instead of dedicated drives in the shelves. While this can be turned off, in most cases it is not necessary to.

Equally, newer models of ONTAP systems have a much smaller root aggregate requirement as a lot of data is in fact already moved to the internal SSDs already present in the systems. For example a FAS2650 requires a 442GB root aggregate, while a FAS2750 only needs a 192GB one.

However, a root aggregate and root volume on the shelves will likely remain in place for some time, due to the way that failover/takeover works, specifically mailboxes. 

Thanks for the feedback.