mdstat: resync=DELAYED

mdstat: resync=DELAYED

[Eric Pretorious]

Hello, All:

I'm configuring a SuperMicro 5013CM8 (with on-board Adaptec AIC-7902B U320 
SCSI controller controlling two Seagate ST373207LC 73GB U320 hard-drives) and 
am experiencing random crashes: The system ocassionally blurts out a bunch of 
stuff about the SCSI system and then freezes.

Checking the contents of /proc/mdstat I see a potential red-flag:

%> cat /proc/mdstat
Personalities : [raid1]
read_ahead 1024 sectors
Event: 5
md2 : active raid1 sdb1[1] sda1[0]
      48064 blocks [2/2] [UU]
        resync=DELAYED
md0 : active raid1 sdb2[1] sda2[0]
      7341632 blocks [2/2] [UU]
        resync=DELAYED
md1 : active raid1 sdb3[1] sda3[0]
      10482304 blocks [2/2] [UU]
        resync=DELAYED
md3 : active raid1 sdb6[1] sda6[0]
      1052160 blocks [2/2] [UU]
        resync=DELAYED
md4 : active raid1 sdb7[1] sda7[0]
      50660864 blocks [2/2] [UU]
      [======>..............]  resync = 30.4% (15410224/50660864) 
finish=56.9min speed=10315K/sec

What does this mean? How can I fix it?

-- 
Eric P.,
Truckee, CA

Re: mdstat: resync=DELAYED

[Brad Campbell]

Eric Pretorious wrote:
> Hello, All:
> 
> I'm configuring a SuperMicro 5013CM8 (with on-board Adaptec AIC-7902B U320 
> SCSI controller controlling two Seagate ST373207LC 73GB U320 hard-drives) and 
> am experiencing random crashes: The system ocassionally blurts out a bunch of 
> stuff about the SCSI system and then freezes.

> md3 : active raid1 sdb6[1] sda6[0]
>       1052160 blocks [2/2] [UU]
>         resync=DELAYED
> md4 : active raid1 sdb7[1] sda7[0]
>       50660864 blocks [2/2] [UU]
>       [======>..............]  resync = 30.4% (15410224/50660864) 
> finish=56.9min speed=10315K/sec
> 
> What does this mean? How can I fix it?
> 

That in itself is not a problem.
The raid subsystem is not going to resync more than one array at a time here, or else your drive 
heads would thrash themselves silly. It will progress its way up the list as each resync completes.

A dead restart on my old server used to do exactly the same thing.
As for your SCSI problems, I'm afraid I can't help.

Regards,
Brad
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