Re: Raid5 reshape

["Nigel J. Terry" <nigel@nigelterry.net>]

Neil Brown wrote:
> On Saturday June 17, nigel@nigelterry.net wrote:
>   
>> Any ideas what I should do next? Thanks
>>
>>     
>
> Looks like you've probably hit a bug.  I'll need a bit more info
> though.
>
> First:
>
>   
>> [root@homepc ~]# cat /proc/mdstat
>> Personalities : [raid5] [raid4]
>> md0 : active raid5 sdb1[1] sda1[0] hdc1[4](S) hdb1[2]
>>       490223104 blocks super 0.91 level 5, 128k chunk, algorithm 2 [4/3] 
>> [UUU_]
>>       [=>...................]  reshape =  6.9% (17073280/245111552) 
>> finish=86.3min speed=44003K/sec
>>
>> unused devices: <none>
>>     
>
> This really makes it look like the reshape is progressing.  How
> long after the reboot was this taken?  How long after hdc1 has hot
> added (roughly)?  What does it show now?
>
> What happens if you remove hdc1 again?  Does the reshape keep going?
>
> What I would expect to happen in this case is that the array reshapes
> into a degraded array, then the missing disk is recovered onto hdc1.
>
> NeilBrown
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>   
I don't know how long the system was reshaping before the power went 
off, and then I had to restart when the power came back. It claimed it 
was going to take 430 minutes, so 6% would be about 25 minutes, which 
could make good sense, certainly it looked like it was working fine when 
I went out.

Now nothing is happening, it shows:

[root@homepc ~]# cat /proc/mdstat
Personalities : [raid5] [raid4]
md0 : active raid5 sdb1[1] sda1[0] hdc1[4](S) hdb1[2]
      490223104 blocks super 0.91 level 5, 128k chunk, algorithm 2 [4/3] 
[UUU_]
      [=>...................]  reshape =  6.9% (17073280/245111552) 
finish=2281.2min speed=1665K/sec

unused devices: <none>
[root@homepc ~]#

so the only thing changing is the time till finish.

I'll try removing and adding /dev/hdc1 again. Will it make any 
difference if the device is mounted or not?

Nigel