Hello all, I'm looking for comments on a setup I'm working on.. I'm building three-way mirror with (at least) one removable drive. My intention is solve the offsite backup problem by allowing my users to simply unplug the removable drive, take it away, and replug it (or a replacement later) without having to think about anything. It's three-way so I have redundancy when the removable is gone. I'm experimenting with mdadm to figure out various solutions to build the setup. My approach is to use the PROGRAM feature of mdadm to run a script when the removable device "fails", the script will briefly sleep to let subsystems settle down, then call mdadm to remove to failed device. On reconnect of the device, I can use udev to tell me which socket the drive was connected (to determine if it's RAID related even I care about), briefly sleep again, then call mdadm to add the device back to the array. I could write a udev rule to make the dev names permanent, i.e. corresponding to the socket so I don't have to deal with incremental or varying sda, sdb, sdc, style names. But it might not be worth it.. I'll just be using "mdadm <MD> --remove detached", and "mdadm <MD> --add <NEW_DEV_PATH>". I'm just wondering if I understand things correctly. Should I be looking at writing the array config into mdadm.conf and doing something mdadm --assemble? I think not because the array will already be active (and therefore assembled), just degraded. Thoughts? Ultimately, I'd like to do this ontop of an EVMS BBR (bad block relocation) segment manager to buy me time when bad blocks are encountered on array drives. (As opposed to have the entire drive offlined immediately.) Thanks, Richard - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
