On August 28, 2019 5:51:02 PM PDT, Marc Oggier <marc.ogg...@megavolts.ch> wrote: >Hi All, > >I am currently buidling a small data server for an experiment. > >I was wondering if the features of the spare volume introduced a couple > >of years ago (ttps://patchwork.kernel.org/patch/8687721/) would be >release soon. I think this would be awesome to have a drive installed, >that can be used as a spare if one drive of an array died to avoid >downtime. > >Does anyone have news about it, and when it will be officially in the >kernel/btrfs-progs ? > >Marc > >P.S. It took me a long time to switch to btrfs. I did it less than a >year ago, and I love it. Keep the great job going, y'all
I've been thinking about this issue myself, and I have an (untested) idea for how to accomplish something similar. My file server has three disks in a btrfs raid1. I added a fourth disk to the array as just a normal, participating disk. I keep an eye on the usage to make sure that I never exceed 3 disk's worth of usage. That way, if one disk dies, there are still enough disks to mount RW (though I may still need to do an explicit degraded mount, not sure). In that scenario, I can just trigger an online full balance to rebuild the missing raid copies on the remaining disks. In theory, minimal to no downtime. I'm curious if anyone can see any problems with this idea. I've never tested it, and my offsite backups are thorough enough to survive downtime anyway. --Sean
