Suman C posted on Tue, 14 Oct 2014 07:48:01 -0700 as excerpted: > Here's a simple raid1 recovery experiment that's not working as > expected. > > kernel: 3.17, latest mainline progs: 3.16.1 > > I started with a simple raid1 mirror of 2 drives (sda and sdb). The > filesystem is functional, I created one subvol, put some data, > read/write tested etc.. > > yanked the sdb out. (this is physical/hardware). btrfs fi show prints > drive missing, as expected. > > powered the machine down. removed the "bad"(yanked out sdb) drive and > replaced it with a new drive. Powered up the machine. > > The new drive shows up as sdb. btrfs fi show still prints drive missing. > > mounted the filesystem with ro,degraded > > tried adding the "new" sdb drive which results in the following error. > (-f because the new drive has a fs from past) > > # btrfs device add -f /dev/sdb /mnt2/raid1pool /dev/sdb is mounted
While I'm not sure it'll get you past the error, did you try... # btrfs replace ... That's the new way to /replace/ a missing device, adding a new one and deleting the old one (which can be missing) at the same time. See the btrfs-replace manpage. While the btrfs-replace manpage says that you have to use the <devid> format if the device is missing, it isn't particularly helpful in telling what that format actually is. Do a btrfs fi show and use the appropriate devid /number/ from there. =:^) Please report back as I'm using btrfs raid1 as well, but my own tests are rather stale by this point and I'd have to figure it out as I went. So I'm highly interested in your results. =:^) (FWIW, personally I'd have made that btrfs device replace, instead of btrfs replace, to keep it grouped with the other device operations, but whatever, it's its own top-level command, now. Tho at least the btrfs-device manpage mentions btrfs replace and its manpage as well. But I still think having replace as its own top-level command is confusing.) -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
