Replacing a 1.5TB drive with 4TB in Drobo Gen 2 that has 2x1.5 & 2x2TB drives. Is hot swap still best practice? Or is it better to power down? Can Drobo remain online? During rebuild, which could take days I understand, can users still access & what impact on Drobos performance during rebuild?
Thanks.
Mac Pro 3,1, OSX Snow Leopard.
Yes you can hot-swap drives but only one per each rebuild cycle.
Rebuild time will depend on actual data size and user activity during rebuild.
drobo will remain available during rebuild time, but I would suggest to minimize user activity so that rebuild can be finished as soon as possible.
Thanks for the reply. I have stressed to client the more activity the longer the rebuild. Also, do I need to take Drobo off line during swap?
Thanks again.
hi i dont think you need to take it offline, but if they use it a lot it will definitely impact the length (and risk) of the unit.
if you have the facility, you could take a backup of the data while the unit is online, as a precaution, so that in case something went wrong if you were to need to leave it upgrading while under use, that you could at least have a backup.
(its appreciated though that such a backup will add some cost and time overheads, but if the data / or client is important, it might be worth it, even if you need to suggest cross-charging them a small amount for part of the cost of the backup drive space, which you might also be able to re-use with other clients in a similar way for other upgrade plans).[hr]
btw maybe not the best time to mention it 
but i think once you are able to also upgrade a 2nd drive into 4tb, the amount of usable space will greatly increase, because drobo uses the largest drive’s equivalent capacity size of space for recovery, and when you upgrade into 4tb+1.5tb+2tb+2tb, it will see it as 5.5tb, but when it becomes 4+4+2+2 it will see it as 8tb. times about 0.9 for actual.
Thanks for the reply. New problem. When attempting to add the 2nd 4TB drive as a replacement for a !.5TB drive (new config would be 4+4+2+2) I was prompted if I wanted to create another volume, options were Yes and Remind me later. Since I didn’t want another volume, I chose remind me later, and then I received an error message that my data was not protected, and the newly inserted 4TB drive slot was red, all other 3 drives were green. I ejected the newly inserted 4TB and reinserted the old 1.5TB and now unit is rebuilding, apparently normally. Any reason I couldn’t upgrade? Someone suggested that the original volume configuration wouldn’t support another 4TB and only option for more space is backup, reformat entire Drobo to a new volume configuration, then retrieve data from backup. Any input?
hi sem,
when you add more space to your drobo via larger drives, the drobo might need to create an extra volume (drive letter etc) for it to use.
what is the max size shown on your existing one?
(usually this will be setup at the start of your drobo usage, and is the largest possible volume size per volume).
so for example i set my volumes to be 2tb max per volume as it suited me best.
when i added more space to my drobo, it asked me to create another volume and i said yes.
i ended up with a 2nd volume of 2tb max as well. (though i know that my drobo only has enough actual space on the 2nd volume for less than that as per what dashboard tells me).
in your case, i think its ok to create another volume for your extra space to use (unless you absolutely are not happy with that option) - either way though, just make sure you dont try to overfill that 2nd volume.