Adding disks to existing RAID array

Solution 1:

From the PERC H730P Mini web interface you can add new disks to your existing RAID array.

Adding 2x 3TB drives to your existing RAID 10 made out of 4x1.9TB, assuming you manage it without any problems, will increase your space with those 3TB (around 2.7 real TB).

According to the official Dell documentation, page 25, increase of capacity by adding disks into a RAID 10 is supported.

But it all depends on controller being bug-free - in theory there is nothing what prevents you from extending with the controller and stripe across 3 mirrored pairs 3x2 disks from 2x2 original. Most of the time, such maneuvers work, but as in anything, there's a risk. I had a situation where simply adding a hot-spare changed the diskID causing the whole RAID to be unaccessible by the OS. Had to result to restoring from backups as time was too limited to try other solutions.

You should take all precautions to save all your data before attempting to expand your RAID 10 array.