1

I have this Linux RAID5 array with 4 2TB harddisks, with 3 active device and one spare, giving me a total disk size of around 6TB.

Recently one drive (sdd) is starting to give me some SMART errors, so I've decided to replace it before it really dies. So I bought a new drive and replaced the old sdd. During the reconstruction, another drive (sdc) died with a lot of errors. (To be honest I'm not sure whether sdc dies during or after the reconstruction).

For now, they look like this:

# mdadm -E /dev/sd[a-d]1 | egrep '/dev/sd|Event|Role'
/dev/sda1:
         Events : 51270
   Device Role : Active device 0
/dev/sdb1:
         Events : 51270
   Device Role : Active device 1
/dev/sdc1:
         Events : 51261
   Device Role : Active device 2
/dev/sdd1:
         Events : 51270
   Device Role : spare

Looking at event count, it seems like only sdc is out of sync. But I'm not able to assemble the array again as sdd1 is a spare, while sdc1 is bad:

# mdadm --assemble /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdd1
mdadm: /dev/md0 assembled from 2 drives and 1 spare - not enough to start the array.

# mdadm --assemble /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdd1
mdadm: /dev/md0 assembled from 2 drives and 1 spare - not enough to start the array.

How should I go about this? There are a few things that are unclear to me:

  1. Are sda1 sdb1 sdd1 enough to assemble the array without sdc1?

  2. I have tried --assemble --force as suggested by some recovery guide, but all that does is to cause the array to come up and reconstruct sdd1 again, and it fails with sdc1 again eventually (after like 12 hours), and goes back to the same state.

  3. Can I simply replace sdc1 now with a new disk?

Thanks!

0

0

You must log in to answer this question.

Browse other questions tagged .