On Sun, Apr 3, 2016 at 4:19 PM, Kai Krakow <hurikhan77@xxxxxxxxx> wrote: > BTW: Is it possible to use my backup drive (it's btrfs single-data > dup-metadata, single device) as a seed device for my newly created > btrfs pool (raid0-data, raid1-metadata, three devices)? Yes. I just tried doing the conversion to raid1 before and after seed removal, but with the small amount of data (4GiB) I can't tell a difference. It seems like -dconvert=raid with seed still connected makes two rw copies (i.e. there's a ro copy which is the original, and then two rw copies on 2 of the 3 devices I added all at the same time to the seed), and the 'btrfs dev remove' command to remove the seed happened immediately, suggested the prior balances had already migrated copies off the seed. This may or may not be optimal for your case. Two gotchas. I ran into this bug: btrfs fi usage crash when volume contains seed device https://bugzilla.kernel.org/show_bug.cgi?id=115851 And there is a phantom single chunk on one of the new rw devices that was added. Data,single: Size:1.00GiB, Used:0.00B /dev/dm-8 1.00GiB It's still there after the -dconvert=raid1 and separate -mconvert=raid and after seed device removal. A balance start without filters removes it, chances are had I used -dconvert=raid1,soft it would have vanished also but I didn't retest for that. > I guess the > seed source cannot be mounted or modified... ? -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
