How to get the devid of a missing device

[Wolfgang Mader <Wolfgang_Mader@brain-frog.de>]

Hello,

I have a raid10 with one device missing. I would like to use btrfs replace to 
replace it. However, I am unsure on how to obtain the devid of the missing 
device. Having the filesystem mounted in degraded mode under mnt, btrfs fs 
show /mnt returns

sudo btrfs filesystem show /mnt
Label: 'dataPool'  uuid: b5f082e2-2ce0-4f91-b54b-c2d26185a635
        Total devices 4 FS bytes used 665.88GiB
        devid    2 size 931.51GiB used 336.03GiB path /dev/sdb
        devid    4 size 931.51GiB used 336.03GiB path /dev/sdd
        devid    5 size 931.51GiB used 336.03GiB path /dev/sde
        *** Some devices missing

but does not mention the devid of the missing device. The device stat is

sudo btrfs device stats /mnt 
[/dev/sdb].write_io_errs   0 
[/dev/sdb].read_io_errs    0 
[/dev/sdb].flush_io_errs   0 
[/dev/sdb].corruption_errs 0 
[/dev/sdb].generation_errs 0 
[(null)].write_io_errs   1448 
[(null)].read_io_errs    0 
[(null)].flush_io_errs   0 
[(null)].corruption_errs 0 
[(null)].generation_errs 0 
[/dev/sdd].write_io_errs   0 
[/dev/sdd].read_io_errs    0 
[/dev/sdd].flush_io_errs   0 
[/dev/sdd].corruption_errs 0 
[/dev/sdd].generation_errs 0 
[/dev/sde].write_io_errs   0 
[/dev/sde].read_io_errs    0 
[/dev/sde].flush_io_errs   0 
[/dev/sde].corruption_errs 0 
[/dev/sde].generation_errs 0


Btw, the file system is too old for skinny metadata and extended inode refs. 
If I do a btrfs replace or a btrfs device add, must I myself ensure that the 
new features are not enables for the new device which is to be added?

Thank!
Wolfgang