On Sat, Jan 23, 2016 at 05:03:15PM -0700, Chris Murphy wrote:

Just make sure you have backups before, during, and after all of this,
which should be the case no matter Btrfs or not. Mixed extent types
should work fine, but who knows you could get into an edge case at a
later time for all anyone knows. Looks like skinny extent became
default in btrfs-progs 3.18.

OK, disks have arrived, and I've completed the first replace.
Interestingly enough, the replace seems to have succeeded, however btrfs
fi show doesn't seem to think so.

Dmesg:
[Wed Jan 27 13:03:09 2016] BTRFS info (device sdb1): disk space caching
is enabled
[Wed Jan 27 13:03:09 2016] BTRFS: has skinny extents
[Wed Jan 27 13:03:09 2016] BTRFS: bdev /dev/sdb1 errs: wr 0, rd 186,
flush 0, corrupt 0, gen 0
[Wed Jan 27 13:05:23 2016]  sdc: sdc1
[Wed Jan 27 13:05:25 2016]  sdc: sdc1
[Wed Jan 27 13:08:37 2016] BTRFS: dev_replace from /dev/sdb1 (devid 2)
to /dev/sdc1 started
[Wed Jan 27 16:34:49 2016] BTRFS: dev_replace from /dev/sdb1 (devid 2)
to /dev/sdc1 finished

Btrfs fi show:
warning, device 3 is missing
warning, device 3 is missing
warning devid 3 not found already
Label: none  uuid: 490b8b7c-59c4-45dc-ac63-6a90f0966776
        Total devices 2 FS bytes used 1.45TiB
		devid    1 size 1.82TiB used 1.52TiB path /dev/sda1
		*** Some devices missing

I haven't rebooted or remounted yet, so I'm curious if this is a bug,
a normal thing that is fixed by a reboot, or what.

Still running the same versions from my original email, but here they
are again:

Linux rat 4.3.3-3-ARCH #1 SMP PREEMPT Wed Jan 20 08:12:23 CET 2016
x86_64 GNU/Linux

btrfs-progs v4.3.1


Thanks,

--Sean