3

I removed a faulty disk from my RAID5 with mdadm --manage /dev/md0 -r /dev/sdd1 and replaced it with a new one. I tried to add it with mdadm --manage /dev/md0 -a /dev/sdd1 but it's only added as a spare disk.

mdadm --detail /dev/md0
/dev/md0:
        Version : 1.0
  Creation Time : Mon Jul 13 20:08:27 2015
     Raid Level : raid5
     Array Size : 14651324160 (13972.59 GiB 15002.96 GB)
  Used Dev Size : 2930264832 (2794.52 GiB 3000.59 GB)
   Raid Devices : 6
  Total Devices : 7
    Persistence : Superblock is persistent

  Intent Bitmap : Internal

    Update Time : Tue Jul 14 09:11:21 2015
          State : active
 Active Devices : 6
Working Devices : 7
 Failed Devices : 0
  Spare Devices : 1

         Layout : left-symmetric
     Chunk Size : 128K

           Name : creadata:0  (local to host creadata)
           UUID : c41c15fd:6e7deae3:5cace8e0:4bf7e244
         Events : 7459

    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1
       2       8       65        2      active sync   /dev/sde1
       3       8       81        3      active sync   /dev/sdf1
       4       8       97        4      active sync   /dev/sdg1
       6       8      113        5      active sync   /dev/sdh1

       7       8       49        -      spare   /dev/sdd1

How can I tell mdadm to resync the array with the new disk?

Improve this question

3 Answers 3

Reset to default
1

You should check if your raid is frozen:

cat /sys/block/md0/md/sync_action

and if it is use

echo repair > /sys/block/md0/md/sync_action

to get it started (check with cat /proc/mdstat)

Improve this answer
0

Have you tried to run the following 

mdadm --manage /dev/md0 -a /dev/sdd1

If yes please try :

mdadm --assemble --scan

or

mdadm --assemble /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdg1 /dev/sdh1
Improve this answer
1
  • Yes. Still the new disk is listed as spare: mdadm --assemble --force /dev/md0 /dev/sd[bcdefgh]1 mdadm: /dev/md0 has been started with 6 drives and 1 spare. Commented Jul 14, 2015 at 8:38
0

According to the mdadm output, there's no need to resync.

You've got a RAID 5 array with 15TB of usable space, made out of 3TB drives. Such an array needs six drives for normal operation: 5 data drives and 1 parity drive. The mdadm output doesn't show any of the drives as failed, so when you add a seventh drive to the array, mdadm configures it as a hot spare.

Improve this answer

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.