Facing an interesting challenge. I updated a few machines in... remote places, & in so doing had to run the installer sans RAID (it complained about different machines in different ways) in a hurry, & now I address the challenge of enRAIDing a system by remote control.
I’ve grabbed a disk image of one of the remote machines, & plugged it into a local machine as a test-bed. This has revealed an immediate issue: the SATA controller in this machine is different to either of the others, so it won’t boot the disk image.
At the moment, I’ve booted a rescue image, borrowed part of the prospective RAID partner-drive & am bzip2’ing images of each partition into the borrowed partition, to implement a simple worst-case restore scenario.
When that’s secure, I’ll get into making the confused SATA drivers happy, then use the resulting bootable hard disk to walk through the process of making a small chroot-ish area on a transient partition, then walking the machine through switching opensshd into that, then...
Copying the live partitions into one-partition RAID versions of themselves, then unmounting & “reformatting” each live partition into a RAID component, joining that to (updating it from) the freshly-copied RAIDed version of itself on the secondary disk, remounting it again, then refrain for each. The exciting part is going to be booting from the transient partition into a system with working LAN & opensshd so I can reRAID the root partitions.
By remote control. Watching someone try this via ’doze would be... entertaining. For the onlookers.
Stay tuned for an (eventual) outcome.