Speed Up Adding a Drive to a Mirror
I am using SoftRaid XT 6.05 in an M1 Mac Mini connected to an OWC Mercury Elite Pro Quad enclosure. I installed a single 10TB WD Red drive and copied 4TB of data to it over the network from a Windows server. Then I converted the volume to a mirror and added a second 10TB drive to the mirror. It's now in the process of rebuilding the mirror, and that process is going to take between 12 and 18 hours. While I'm happy that the process is so simple, it would be nice if SoftRaid was smarter about knowing that there was only 4TB of data in use on the drive and thus didn't need to copy 6TB of empty space. Is there something I should have done to speed up the process? I'm thinking it would have been much faster if I had initialized both drives as a mirror before copying the data, but that wasn't an option as the second drive was the source of the data on the Windows server and was moved to the Mac after the data was copied over the network to the first drive.
First time you rebuild, it is slow, as the whole volume has to be rebuilt. Subsequent rebuilds would be only the changed areas of the disk.
Remember you can be using the volume while it is rebuilding, though.