Re: add new disk with dd

On czwartek, 29 kwietnia 2021 10:52:21 CEST d tbsky wrote:

however dd may also copy the mdadm superblock which include internal
bitmap(since I don't caculate correct size). I don't know if there is
risk that mdadm will be confused with the bitmap in new disk. although
I have tried and it seems work fine.
should I disable internal bitmap before add new disk? 

No.

or mdadm will
understand the superblock/bitmap at new disk is invalid and just
overwrite everything?

Should in most cases [1], but IMHO it's good idea to
mdadm --zero-superblock /dev/YOU_ARE_SURE_IS_ONE_YOU_WANT_TO_ADD
before adding disk already used somewhere else.

BTW,  IMHO it's better to clone partition layout, and than install bootloaders 
instead of dding disk.

[1] If disk/part was already used / cloned in same array it's bitmap may be 
recognized, not synced, resulting likely broken array.

-- 
Mateusz 
(...) mam brata - poważny, domator, liczykrupa, hipokryta, pobożniś,
	krótko mówiąc - podpora społeczeństwa."
		Nikos Kazantzakis - "Grek Zorba"