Re: btrfs: convert metadata from raid5 to raid1

Graham Cobb
2020-02-17T18:05:30Z

On 17/02/2020 14:17, Hugo Mills wrote:
> On Mon, Feb 17, 2020 at 03:12:35PM +0100, Menion wrote:
>> ok thanks
>> I have launched it (in a tmux session), after 5 minutes the command
>> did not return yet, but dmesg and btrfs balance status
>> /array/mount/point report it in progress (0%).
>> Is it normal?
>
> Yes, it's got to rewrite all of your metadata. This can take a
> while (especially if you have lots of snapshots or reflinks -- such as
> from running a deduper). You should be able to see progress happening
> fairly regularly in dmesg. This is typically one chunk every minute or
> so, although some chunks can take much *much* longer.

Also, you can watch what is happening by using "btrfs filesystem usage
/your/mount/point". You should see "Metadata,RAID5:" going down and
"Metadata,RAID1" going up. I often leave:

watch -n 10 btrfs fi usage /mount/point

running in a window while doing these sorts of things so I can see how
things are going at a glance.