0

Trying to make myself familiar with some of the raid management options before using the actual devices. So I am working with a few small partitions on a USB-stick.

The goal is to extend an existing raid6 with 4 partitions with an additional partition. I used

mdadm --add /dev/md127 /dev/sdd9
mdadm -v --grow --raid-devices=5 /dev/md127

This seems to start the reshape process successfully. However, the reshape has been hanging at 0% for about an hour already:

as01449@P-H-287-04:~> cat /proc/mdstat                                                                                                                              
Personalities : [raid6] [raid5] [raid4]                                                                                                                                           
md127 : active raid6 sdd9[4] sdd8[3] sdd7[2] sdd6[1] sdd5[0]                                                                                                                      
      2099200 blocks super 1.2 level 6, 512k chunk, algorithm 2 [5/5] [UUUUU]                                                                                                     
      [>....................]  reshape =  0.0% (0/1049600) finish=41.7min speed=406K/sec                                                                                          

unused devices: <none>                                                                                                                                                            
as01449@P-H-287-04:~> sudo mdadm --detail /dev/md127                                                                   /dev/md127:                                                                                                                                                                       
        Version : 1.2                                                                                                                                                             
  Creation Time : Thu Nov 10 03:52:45 2016                                                                                                                                        
     Raid Level : raid6                                                                                                                                                           
     Array Size : 2099200 (2.00 GiB 2.15 GB)                                                                                                                                      
  Used Dev Size : 1049600 (1025.17 MiB 1074.79 MB)                                                                                                                                
   Raid Devices : 5
  Total Devices : 5
    Persistence : Superblock is persistent

    Update Time : Thu Nov 10 04:19:00 2016
          State : clean, reshaping 
 Active Devices : 5
Working Devices : 5
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

 Reshape Status : 0% complete
  Delta Devices : 1, (4->5)

           Name : P-H-287-04.site:raidbackup  (local to host P-H-287-04.site)
           UUID : a8bed6ee:57936286:509a6406:63a314e3
         Events : 22

    Number   Major   Minor   RaidDevice State
       0       8       53        0      active sync   /dev/sdd5
       1       8       54        1      active sync   /dev/sdd6
       2       8       55        2      active sync   /dev/sdd7
       3       8       56        3      active sync   /dev/sdd8
       4       8       57        4      active sync   /dev/sdd9

The estimated finish time is just growing constantly. What am I missing?

1 Answer 1

0

man mdadm:

   --backup-file=
          This is needed when --grow is used to  increase  the  number  of
          raid-devices  in  a RAID5 or RAID6 if there are no spare devices
          available, or to shrink, change RAID level or layout.   See  the
          GROW  MODE section below on RAID-DEVICES CHANGES.  The file must
          be stored on a separate device, not  on  the  RAID  array  being
          reshaped.
1
  • Thanks. Two short follow-up questions: how do I abort the current reshape process? And how large will the backup file grow? Is it only needed for some metadata or will it contain an actual backup of the whole device?
    – MechEng
    Nov 9, 2016 at 17:01

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .