I have to recover my md0 RAID software with linux.
Today I've bought 4 disks,all new,all the same type and size.
I have removed the old disk using:
mdadm /dev/md0 --fail /dev/sdd2 mdadm /dev/md0 --remove /dev/sdd2
changed with the new ones:
mdadm /dev/md0 --add /dev/sdd2
Waited for rebuild and it works
Same thing for disk n°3 (sdc2)
On the sdb2 change the RAID started to give a lot of errors,"sector read failed etc" but not on sdb2, but on sdc2 when sdb2 was rebuilding! Then the system put my ext4 raid in R/O mode.
So I rebooted in single user mode(slackware can from initrd) and try to rebuild,of course before removing sdc2(faulty disk) and sdb2(incomplete resync).
I put the old sdb2 disk and tried to start; the array failed. Tried to add sdb2 to the array; itfailed, and told me to stop and reassemble.
mdadm --stop /dev/md0 mdadm /dev/md0 --assemble /dev/sda2 /dev/sdb2 /dev/sdd2
I want to start with 3 disks,then add sdc2 and complete the array. But it failed considering the sda2 and sdd ok,but mark sdb2 as..removed. How to readd sdb2 and rebuild my array?