Re: is this raid5 OK ?

[Bill Davidsen <davidsen@tmr.com>]

Rainer Fuegenstein wrote:
> hi,
>
> 1) the kernel was:
> [root@alfred ~]# uname -a
> Linux alfred 2.6.19-1.2288.fc5xen0 #1 SMP Sat Feb 10 16:57:02 EST 2007 
> i686 athlon i386 GNU/Linux
>
> now upgraded to:
>
> [root@alfred ~]# uname -a
> Linux alfred 2.6.20-1.2307.fc5xen0 #1 SMP Sun Mar 18 21:59:42 EDT 2007 
> i686 athlon i386 GNU/Linux
>
> OS is fedora core 6
>
> [root@alfred ~]# mdadm --version
> mdadm - v2.3.1 - 6 February 2006
>
> 2) I got the impression that the old 350W power supply was to weak, I 
> replaced it by a 400W version.
>
> 3) re-created the raid:
>
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hde1
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hdf1
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hdg1
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hdh1
> [root@alfred ~]# mdadm --create --verbose /dev/md0 --level=5 
> --raid-devices=4 --spare-devices=0 /dev/hde1 /dev/hdf1 /dev/hdg1 
> /dev/hdh1
> mdadm: layout defaults to left-symmetric
> mdadm: chunk size defaults to 64K
> mdadm: size set to 390708736K
> mdadm: array /dev/md0 started.
> [root@alfred ~]# cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 hdh1[4] hdg1[2] hdf1[1] hde1[0]
>       1172126208 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
>
> unused devices: <none>
>
> same as before.
>
> 4) did as dan suggested:
>
> [root@alfred ~]# mdadm -S /dev/md0
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hde1
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hdf1
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hdg1
> [root@alfred ~]# mdadm --misc --zero-superblock /dev/hdh1
> [root@alfred ~]# mdadm --create /dev/md0 -n 4 -l 5 /dev/hd[efg]1 missing
> mdadm: array /dev/md0 started.
> [root@alfred ~]# cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 hdg1[2] hdf1[1] hde1[0]
>       1172126208 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
>
> unused devices: <none>
> [root@alfred ~]# mdadm --add /dev/md0 /dev/hdh1
> mdadm: added /dev/hdh1
> [root@alfred ~]# cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 hdh1[4] hdg1[2] hdf1[1] hde1[0]
>       1172126208 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
>       [>....................]  recovery =  0.0% (47984/390708736) 
> finish=406.9min speed=15994K/sec
>
> unused devices: <none>
>
> seems like it's working now - tnx !

This still looks odd, why should it behave like this. I have created a 
lot of arrays (when I was doing the RAID5 speed testing thread), and 
never had anything like this. I'd like to see dmesg to see if there was 
an error reported regarding this.

I think there's more going on, the original post showed the array as up 
rather than some building status, also indicates some issue, perhaps. 
What is the partition type of each of these partitions? Perhaps there's 
a clue there.

-- 
bill davidsen <davidsen@tmr.com>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979