On 26/05/2020 04:40, Jonas Fisher wrote:
Hi all,
I got a raid1 composed with 2 disks
/dev/sda -- 2T
/dev/sdb -- 4T
mdadm version is 3.3 and md metadata version is 1.0
That's a well ancient mdadm, you need to upgrade ...
At first, I was only using 1T of the each disk,
then I grew the array recently with the command
mdadm --grow /dev/md1 --size=1951944704K
I also tried to add the internal bitmap after expansion finished
mdadm --grow /dev/md1 --bitmap=internal
But I got the following message
mdadm: failed to create internal bitmap - chunksize problem.
I found that Avail Dev Size in superblock examine of two disks
are the same, same as the value I set when I expanded the array (1951944704K).
Makes sense, it's a mirror ...
Then I found that in mdadm bitmap chunksize calculation,
in function add_internal_bitmap1 (super1.c)
variable "room" and and "max_bits" seems to be overflowed under this situation
Could well be fault of the old mdadm ...
I was wondering is this because mdadm set the size of the rdevs in the array
before doing expansion (in function Grow_reshape)
that caused the sb->data_size not equals to actual raw device size
and consequently led to bitmap chunksize calculation error
or it is simply a data type issue.
Thanks,
Download and run a new mdadm. If the problem still persists, then I
guess the mdadm guys will take a look.
https://raid.wiki.kernel.org/index.php/Linux_Raid
https://raid.wiki.kernel.org/index.php/A_guide_to_mdadm#Getting_mdadm
It seems odd to be mirroring a 2TB and 4TB, but never mind. It's not
(that much) a problem if you're using desktop drives for a mirror, but
if you do get a new 4TB drive, read the advice on the website and make
sure you get a proper raid drive.
Cheers,
Wol
