missing superblock on RAID5

missing superblock on RAID5

[Victor]

At the time I created the RAID array I thought it had superblocks,
however if I use mdadm I get these results:

# mdadm --query /dev/md0
/dev/md0: 230.08GiB raid5 4 devices, 0 spares. Use mdadm --detail for
more detail.
/dev/md0: No md super block found, not an md component.

If  the array really shouldn't have a superblock, is it possible to add
one (maybe marking a device faulty and readding it and repeating this
for each device)?


Thanks in advance,

Victor

Re: missing superblock on RAID5

[Victor]

Now that you mention it I remember to have read somewhere that suberblocks
are written at the end of _partitions_ and not arrays.

Thanks for enlighten me :)

Maybe another stupid question:
# mdadm --detail /dev/md0
/dev/md0:
        Version : 00.90.00
  Creation Time : Sun May 18 14:19:37 2003
     Raid Level : raid5
     Array Size : 241254336 (230.08 GiB 247.04 GB)
    Device Size : 80418112 (76.69 GiB 82.35 GB)
   Raid Devices : 4
  Total Devices : 5
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Wed Oct  8 23:53:50 2003
          State : dirty, no-errors
 Active Devices : 4
Working Devices : 4
 Failed Devices : 1
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

    Number   Major   Minor   RaidDevice State
       0       3       65        0      active sync
/dev/ide/host0/bus0/target1/lun0/part1
       1      22        1        1      active sync
/dev/ide/host0/bus1/target0/lun0/part1
       2      33        1        2      active sync
/dev/ide/host2/bus0/target0/lun0/part1
       3      34        1        3      active sync
/dev/ide/host2/bus1/target0/lun0/part1
           UUID : d8e2995c:dac28dbb:042eb748:bad0f5d6
         Events : 0.52


It says (or at least I think it says) that this array has 5 devices of which
one is faulty. That's not true, it consists only out of 4 devices.

Victor



rob wrote:

> from my sys:
> root@fbc5:/etc # mdadm --query /dev/md3
> /dev/md3: 4.67GiB raid1 2 devices, 0 spares. Use mdadm --detail for more
> detail.
> /dev/md3: No md super block found, not an md component.
>
> root@fbc5:/etc # mdadm --query /dev/sdd5
> /dev/sdd5: is not an md array
> /dev/sdd5: device 1 in 2 device active raid1 md3.  Use mdadm --examine
> for more detail.
>
> so the superblock is not on the /dev/md3 .
>
> query the disk partition to get the superblock
>
> Victor wrote:
>
> >At the time I created the RAID array I thought it had superblocks,
> >however if I use mdadm I get these results:
> >
> ># mdadm --query /dev/md0
> >/dev/md0: 230.08GiB raid5 4 devices, 0 spares. Use mdadm --detail for
> >more detail.
> >/dev/md0: No md super block found, not an md component.
> >
> >If  the array really shouldn't have a superblock, is it possible to add
> >one (maybe marking a device faulty and readding it and repeating this
> >for each device)?
> >
> >
> >Thanks in advance,
> >
> >Victor
> >
> >
> >-
> >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: missing superblock on RAID5

[rob]

that does look strange.  But I've been using software raid for just a 
couple weeks, so don't know a lot about it.

here is same command on our computer. i have only 2 devices.  looks like 
something is up with yours.  do you have another md device you can check 
the command on? 
 


root@fbc5:~ #  mdadm --detail /dev/md0
/dev/md0:
        Version : 00.90.00
  Creation Time : Tue Sep 30 15:22:45 2003
     Raid Level : raid1
     Array Size : 8337600 (7.95 GiB 8.54 GB)
    Device Size : 8337600 (7.95 GiB 8.54 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Fri Oct 10 08:37:34 2003
          State : dirty, no-errors
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0


    Number   Major   Minor   RaidDevice State
       0       8        6        0      active sync   
/dev/scsi/host0/bus0/target1/lun0/part6
       1       8       22        1      active sync   
/dev/scsi/host0/bus0/target3/lun0/part6
           UUID : 131c021d:7bc1e937:1bea7923:d7eed283
         Events : 0.54



Victor wrote:

>Now that you mention it I remember to have read somewhere that suberblocks
>are written at the end of _partitions_ and not arrays.
>
>Thanks for enlighten me :)
>
>Maybe another stupid question:
># mdadm --detail /dev/md0
>/dev/md0:
>        Version : 00.90.00
>  Creation Time : Sun May 18 14:19:37 2003
>     Raid Level : raid5
>     Array Size : 241254336 (230.08 GiB 247.04 GB)
>    Device Size : 80418112 (76.69 GiB 82.35 GB)
>   Raid Devices : 4
>  Total Devices : 5
>Preferred Minor : 0
>    Persistence : Superblock is persistent
>
>    Update Time : Wed Oct  8 23:53:50 2003
>          State : dirty, no-errors
> Active Devices : 4
>Working Devices : 4
> Failed Devices : 1
>  Spare Devices : 0
>
>         Layout : left-symmetric
>     Chunk Size : 64K
>
>    Number   Major   Minor   RaidDevice State
>       0       3       65        0      active sync
>/dev/ide/host0/bus0/target1/lun0/part1
>       1      22        1        1      active sync
>/dev/ide/host0/bus1/target0/lun0/part1
>       2      33        1        2      active sync
>/dev/ide/host2/bus0/target0/lun0/part1
>       3      34        1        3      active sync
>/dev/ide/host2/bus1/target0/lun0/part1
>           UUID : d8e2995c:dac28dbb:042eb748:bad0f5d6
>         Events : 0.52
>
>
>It says (or at least I think it says) that this array has 5 devices of which
>one is faulty. That's not true, it consists only out of 4 devices.
>
>Victor
>  
>

Re: missing superblock on RAID5

[Victor]

Actually I have 2 arrays and both have a device more than they should.


# mdadm --detail /dev/md1
/dev/md1:
        Version : 00.90.00
  Creation Time : Wed Jul 30 21:49:33 2003
     Raid Level : raid5
     Array Size : 18474496 (17.62 GiB 18.92 GB)
    Device Size : 9237248 (8.81 GiB 9.46 GB)
   Raid Devices : 3
  Total Devices : 4
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Wed Oct  8 23:53:50 2003
          State : dirty, no-errors
 Active Devices : 3
Working Devices : 3
 Failed Devices : 1
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

    Number   Major   Minor   RaidDevice State
       0       3        3        0      active sync
/dev/ide/host0/bus0/target0/lun0/part3
       1      33        2        1      active sync
/dev/ide/host2/bus0/target0/lun0/part2
       2      34        2        2      active sync
/dev/ide/host2/bus1/target0/lun0/part2
           UUID : 7aa04659:9100ac93:b3808182:f11c0b78
         Events : 0.36



rob wrote:

> that does look strange.  But I've been using software raid for just a
> couple weeks, so don't know a lot about it.
>
> here is same command on our computer. i have only 2 devices.  looks
> like
> something is up with yours.  do you have another md device you can
> check
> the command on?
>
>
> root@fbc5:~ #  mdadm --detail /dev/md0
> /dev/md0:
>         Version : 00.90.00
>   Creation Time : Tue Sep 30 15:22:45 2003
>      Raid Level : raid1
>      Array Size : 8337600 (7.95 GiB 8.54 GB)
>     Device Size : 8337600 (7.95 GiB 8.54 GB)
>    Raid Devices : 2
>   Total Devices : 2
> Preferred Minor : 0
>     Persistence : Superblock is persistent
>
>     Update Time : Fri Oct 10 08:37:34 2003
>           State : dirty, no-errors
>  Active Devices : 2
> Working Devices : 2
>  Failed Devices : 0
>   Spare Devices : 0
>
>     Number   Major   Minor   RaidDevice State
>        0       8        6        0      active sync
> /dev/scsi/host0/bus0/target1/lun0/part6
>        1       8       22        1      active sync
> /dev/scsi/host0/bus0/target3/lun0/part6
>            UUID : 131c021d:7bc1e937:1bea7923:d7eed283
>          Events : 0.54
>

Re: missing superblock on RAID5

[rob]

which version of mdadm are you using?

which distribution & release?

Victor wrote:

>Actually I have 2 arrays and both have a device more than they should.
>
>  
>
>

Re: missing superblock on RAID5

[Victor]

mdadm - v1.2.0 - 13 Mar 2003
on Gentoo (something like v1.4 with lots of updates)


rob wrote:

> which version of mdadm are you using?
>
> which distribution & release?
>
> Victor wrote:
>
> >Actually I have 2 arrays and both have a device more than they should.
> >
> >

Re: missing superblock on RAID5

[rob]

my info:
mandrake 9.1
mdadm 1.2.0

 do you have  ARRAY or DEVICE entries in your /etc/mdadm.conf ?
 if so try commenting them out and run the mdadm command again.


 Did the GENTOO mdadm come with a  monitoring script for in /etc/init.d 
?  Mandrake's rpm did not. 
RedHats's mdadm rpm contains  /etc/init.d/mdmonitor  script which does a 
great job running mdadm --monitor.
I used RH's mdmonitor on the Mandrake computer. works great, with just 2 
lines in /etc/mdadm.conf.

 RedHat seems to have software raid implemented better than Mandrake.



Victor wrote:

>mdadm - v1.2.0 - 13 Mar 2003
>on Gentoo (something like v1.4 with lots of updates)
>
>
>  
>
>  
>