Disk replacement fails

Brief description of the problem

I have a RAID10 pool (called Data) with a failed disk. I found Data Loss-prevention and Recovery in Rockstor — Rockstor documentation and following the steps under “Data loss Prevention and Recovery in RAID10 Pools”. Unfortunately, it looks like the BTRFS replace command failed. In addition, after running this command a second disk now shows as detached.

Steps I performed

I followed each step shown on the documentation page posted above:

  1. btrfs fi show originally showed “warning, device 1 is missing”
    • The devices listed under Label: 'Data' are: /dev/sdc, /dev/sdd, and /dev/sde
  2. mount -o degraded /dev/sdc /mnt2/Data
  4. btrfs replace start 1 /dev/sda /mnt2/Data
    • Note: It seems there may be an error in the documentation as it specifies an old drive as the target. This did not make sense to me, and I received an error until I specified my new drive (/dev/sda) as the target.
  5. btrfs replace status /mnt2/Data
    • This showed 0% for a moment, then eventually showed cancelled.
  6. btrfs fi show now shows device 1 and 2 are missing. Also, it shows bytenr mismatch, want=21069824, have=0 and Couldn't read chunk tree which I don’t recall from the first time.

Any help is appreciated. Thanks.