What I am looking to do is, one by one, replace the drives in my current raid array (in a 1680i). After the drives are replaced by their larger counterparts, I want to do an online expand of the array. Can this be done?
I have an Areca ARC-1231 controller, apparently they use the same driver.
These have a separate notion of Raid Set (collection of disks sharing a common size) and Raid Volumes (which span across part of all the disks of the Raid Set and have a defined size and raid level.)
I have not attempted it yet, but querying the Raid Set shows a Min Member Disk Size and no way to set a size by hand, so I guess once you'd have replaced all the disks in the raid set, they will be free capacity on the raid set, at which point you should be able to grow the volume inside the raidset (with the CLI the command is something like
For me, "vsf modify" responded with "success" but didn't make any visible changes in the volume set.
I ended up finding an undocumented command that can be issued in the "Rescue Raid Set" UI in the HTTP interface. The idea is to type "RESETCAPACITY" followed by the RAID set name. In the post I've liked, the default name of "RAIDSET # 000" was used. For me, the Raid Set name was "TopRow" (corresponding to the top row of drives in my cabinet), so I used "RESETCAPACITY TopRow".
That command immediately returns with success. If I view the RaidSet details, I see that the "Total Raw Capacity" is now larger and the "Free Raw Capacity" is non-zero. The RAID Set is now larger!
Clicking on the "Modify Volume set" command, I selected the volume that lives on this RAID set. The "Max Capacity Allowed" was larger, so I edited the "Volume Capacity" field to match that number. I marked "confirm the operation" and Pressed "Submit". That started the volume set initializing; it started at 75% and is counting toward 100%, so this will take some time. (I was expanding from 6 GB available capacity to 8 GB available capacity.)
Once this is done, I just used the Windows "Expand Volume" command in the volume and storage management snap-in in MMC.