strange nr. of devices in array

strange nr. of devices in array

[Christian Kivalo]

hi everybody!

i found out, that the superblock of my raid5 array says it's built out
of 7 disks, but i created it with only 6 disk. the mdadm call used to
create the array was:

mdadm --create /dev/md6 -c 64 -l raid5 -p ls -n 6 --spare-disks=0 \
/dev/hde1 /dev/hdg1 /dev/hdi1 /dev/hdk1 /dev/hdm1 /dev/hdo1

i grep'ed through my .bash_history and that was the only line showing
mdadm --create.

i'm using mdadm version 0.7.2, i think that is pretty old. i will
upgrade to a more recent version and recreate the array.

still i would like to know if i encountered a bug or if thats some other
problem. this mdadm version is the one from debian woody (stable).

output of mdadm --detail /dev/md6

/dev/md6:
        Version : 00.90.00
  Creation Time : Mon Feb  9 00:55:34 2004
     Raid Level : raid5
     Array Size : 781240320 (745.04 GiB 799.99 GB)
    Device Size : 156248064 (149.00 GiB 159.99 GB)
     Raid Disks : 6
    Total Disks : 7
Preferred Minor : 6
    Persistance : Superblock is persistant

    Update Time : Tue Feb 17 20:53:02 2004
          State : dirty, no-errors
  Active Drives : 6
 Working Drives : 6
  Failed Drives : 1
   Spare Drives : 0

         Layout : left-symmetric
     Chunk Size : 64K

    Number   Major   Minor   RaidDisk   State
       0      33        1        0      active sync   /dev/hde1
       1      34        1        1      active sync   /dev/hdg1
       2      56        1        2      active sync   /dev/hdi1
       3      57        1        3      active sync   /dev/hdk1
       4      88        1        4      active sync   /dev/hdm1
       5      89        1        5      active sync   /dev/hdo1
           UUID : 7b22b692:7564eab7:02145e27:9bfc02a2

it seems there are no errors but i don't want to encounter a drive
failure and beeing stuck with a 2 drive failure (i know there are ways
to get a 2 drive failure array back up and working)

thanks in advance
christian

Re: strange nr. of devices in array

[Norman Schmidt]

Hi Christian!

Christian Kivalo schrieb:
> hi everybody!
> 
> i found out, that the superblock of my raid5 array says it's built out
> of 7 disks, but i created it with only 6 disk. the mdadm call used to
> create the array was:
>

> i'm using mdadm version 0.7.2, i think that is pretty old. i will
> upgrade to a more recent version and recreate the array.
> 
> still i would like to know if i encountered a bug or if thats some other
> problem. this mdadm version is the one from debian woody (stable).
> 
> 
> thanks in advance
> christian

Yes, that is a bug in the (very old) 0.7.2 of Debian. Additionally, 
these old versions cannot handle spare devices (after each assemble, you 
hae to add them manually). Use at least mdadm 1.4.0, better the newest 
(I believe 1.5.0). You do not need to recreate the array, simply stop it 
and (re-)assemble it after you have the new mdadm in place - and the bug 
and the wrong output is gone.

Had the same problem (that with the spare device) with SuSE 8.2 and 
Debian Woody...

Bye, Norman.

-- 

Norman Schmidt          Institut fuer Physikal. u. Theoret. Chemie
Dipl.-Chem.             Friedrich-Alexander-Universitaet
schmidt@naa.net         Erlangen-Nuernberg
                         IT-Systembetreuer Physikalische Chemie

Re: strange nr. of devices in array

[Christian Kivalo]

On Sat, 21 Feb 2004 10:19:01 +0100, Norman Schmidt
<norman.schmidt@web.de> wrote:
 
> > i'm using mdadm version 0.7.2, i think that is pretty old. i will
> > upgrade to a more recent version and recreate the array.
> > 
> > still i would like to know if i encountered a bug or if thats some
> > other problem. this mdadm version is the one from debian woody
> > (stable).
> > 
> > 
> > thanks in advance
> > christian
> 
> Yes, that is a bug in the (very old) 0.7.2 of Debian. Additionally, 
> these old versions cannot handle spare devices (after each assemble,
> you hae to add them manually). Use at least mdadm 1.4.0, better the
> newest (I believe 1.5.0). You do not need to recreate the array,
> simply stop it and (re-)assemble it after you have the new mdadm in
> place - and the bug and the wrong output is gone.
> 
> Had the same problem (that with the spare device) with SuSE 8.2 and 
> Debian Woody...
> 

hi!

thanks for that information, i will upgrade to the newest mdadm and try
again.

thanks
christian


> Bye, Norman.
> 
> -- 
> 
> Norman Schmidt          Institut fuer Physikal. u. Theoret. Chemie
> Dipl.-Chem.             Friedrich-Alexander-Universitaet
> schmidt@naa.net         Erlangen-Nuernberg
>                          IT-Systembetreuer Physikalische Chemie
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid"
> in the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: strange nr. of devices in array

[valo lindstroem]

On Sat, 21 Feb 2004 10:19:01 +0100, Norman Schmidt
<norman.schmidt@web.de> wrote:

> Hi Christian!
> 
> Christian Kivalo schrieb:
> > hi everybody!
> > 
> > i found out, that the superblock of my raid5 array says it's built
> > out of 7 disks, but i created it with only 6 disk. the mdadm call
> > used to create the array was:
> >
> 
> > i'm using mdadm version 0.7.2, i think that is pretty old. i will
> > upgrade to a more recent version and recreate the array.
> > 
> > still i would like to know if i encountered a bug or if thats some
> > other problem. this mdadm version is the one from debian woody
> > (stable).
> > 
> > 
> > thanks in advance
> > christian
> 
> Yes, that is a bug in the (very old) 0.7.2 of Debian. Additionally, 
> these old versions cannot handle spare devices (after each assemble,
> you hae to add them manually). Use at least mdadm 1.4.0, better the
> newest (I believe 1.5.0). You do not need to recreate the array,
> simply stop it and (re-)assemble it after you have the new mdadm in
> place - and the bug and the wrong output is gone.
> 
> Had the same problem (that with the spare device) with SuSE 8.2 and 
> Debian Woody...
> 
hi norman!

downloaded and compiled mdadm 1.5.0, reassembled the array with

mdadm -A /dev/md6 --update=summaries

and everything looks like expected now.

thanks
christian

> Bye, Norman.
> 
> -- 
> 
> Norman Schmidt          Institut fuer Physikal. u. Theoret. Chemie
> Dipl.-Chem.             Friedrich-Alexander-Universitaet
> schmidt@naa.net         Erlangen-Nuernberg
>                          IT-Systembetreuer Physikalische Chemie
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid"
> in the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>