mdadm重塑raid6没有启动

Question

试着在使用实际设备之前让自己熟悉一些raid管理选项。所以我在USB上使用几个小分区。

目标是将现有的raid6扩展为4个分区，并添加一个分区。我用

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

这似乎成功地启动了重塑过程。然而，这一重塑已经持续了大约一个小时了：

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

估计的完工时间只是在不断增长。我遗漏了什么？

Answer 1

男子汉：

   --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.