I have a raid5 of 3 disks.
2 of them have bad sectors. Sector 1110 and 1118.
I'm curious to know if these sectors actually contain any data or if they
can just be overwritten.
All 3 disks are partitioned with partition starting at sector 128.
The raid was created some time ago. I have never replaced any of the disks.
mdadm -E of one of the disks shows the following information (just relevent
to the question)
Version : 1.1
Data Offset : 262144 sectors
Super Offset : 0 sectors
Unused Space : before=262072 sectors, after=290 sectors
Doing the math, from offset 0 to 71 I would assume is the superblock. Given
the bad sectors as shown by the kernel logs, 1110 and 1118 would fall in the
unused space.
So if I were to dd if=/dev/zero of=/dev/sda count=262072 seek=200, would
this break my array? This command would be against the whole disk, not
partition.
I do have multiple backups of this system.
FYI, I did initiate a check to verify the data area, and there's no bad
sectors there.
