On 2018/8/30 下午5:13, Pierre Couderc wrote:
> Trying to install a RAID1 on a debian stretch, I made some mistake and
> got this, after installing on disk1 and trying to add second disk  :
> 
> 
> root@server:~# fdisk -l
> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disklabel type: dos
> Disk identifier: 0x2a799300
> 
> Device     Boot Start        End    Sectors  Size Id Type
> /dev/sda1  *     2048 3907028991 3907026944  1.8T 83 Linux
> 
> 
> Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disklabel type: dos
> Disk identifier: 0x9770f6fa
> 
> Device     Boot Start        End    Sectors  Size Id Type
> /dev/sdb1  *     2048 3907029167 3907027120  1.8T  5 Extended
> 
> 
> And :
> 
> root@server:~# btrfs fi show
> Label: none  uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed
>         Total devices 2 FS bytes used 1.10GiB
>         devid    1 size 1.82TiB used 4.02GiB path /dev/sda1
>         devid    2 size 1.00KiB used 0.00B path /dev/sdb1
> 
> ...
> 
> My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks
> in prder to start in degraded mode....
> How to get out ofr that...?

The 2nd device is indeed strange.

Considering how old packages Debian tends to deliver, it should be some
old btrfs-progs.

You could just boot into the system and execute the following commands:

# btrfs device remove 2 <mnt>

Then add a new real device to the fs

# btrfs device add <new device> <mnt>

Then convert the fs to RAID1

# btrfs balance start -dconvert=RAID1 -mconvert=RAID1 <mnt>

Thanks,
Qu

> 
> Thnaks
> PC