What does 'WrongLevel' mean in RAID0 ?

What does 'WrongLevel' mean in RAID0 ?

[J.A. Magallon]

Hi all...

I have a RAID0 setup on top of three IDE drives.
mdadm monitor sends me mesages with:

DeviceDisappeared
/dev/md0
Wrong-Level

The RAID seems to be working well. Any pointer on what does this mean ?

PD: I know it is a bit strange raid, see:

annwn:~# cat /proc/partitions
major minor  #blocks  name

   3     0  245117376 hda
   3     1  245111706 hda1
  22     0  117220824 hdc
  22     1  117218241 hdc1
  22    64  117220824 hdd
  22    65  117218241 hdd1

annwn:~# mdadm -D /dev/md0
/dev/md0:
        Version : 00.90.01
  Creation Time : Mon Sep 13 17:57:08 2004
     Raid Level : raid0
     Array Size : 479547968 (457.33 GiB 491.06 GB)
   Raid Devices : 3
  Total Devices : 3
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Mon Sep 13 17:57:08 2004
          State : clean
 Active Devices : 3
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 0

     Chunk Size : 64K

           UUID : c7c5ec26:ae5a99f9:49fec7a1:7e0dcc69
         Events : 0.12

    Number   Major   Minor   RaidDevice State
       0       3        1        0      active sync   /dev/hda1
       1      22        1        1      active sync   /dev/hdc1
       2      22       65        2      active sync   /dev/hdd1


--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Limited Edition 2005) for i586
Linux 2.6.11-jam14 (gcc 3.4.3 (Mandrakelinux 10.2 3.4.3-7mdk)) #3

Re: What does 'WrongLevel' mean in RAID0 ?

[Neil Brown]

On Tuesday April 12, jamagallon@able.es wrote:
> Hi all...
> 
> I have a RAID0 setup on top of three IDE drives.
> mdadm monitor sends me mesages with:
> 
> DeviceDisappeared
> /dev/md0
> Wrong-Level
> 
> The RAID seems to be working well. Any pointer on what does this
> mean ?

 From  "man mdadm"  (if you know where to look)

       Follow or Monitor
              Monitor  one  or  more  md devices and act on any state changes.
              This is only meaningful for raid1, 4, 5, 6 or  multipath  arrays
              as  only  these  have  interesting state.  raid0 or linear never
              have missing, spare, or failed drives, so there  is  nothing  to
              monitor.

You are presumably trying to monitor a raid0 (which isn't meaningful)
and mdadm is telling you (in its own idiosyncratic way) that it isn't
going to monitor it.

NeilBrown

Re: What does 'WrongLevel' mean in RAID0 ?

[J.A. Magallon]

On 04.12, Neil Brown wrote:
> On Tuesday April 12, jamagallon@able.es wrote:
> > Hi all...
> > 
> > I have a RAID0 setup on top of three IDE drives.
> > mdadm monitor sends me mesages with:
> > 
> > DeviceDisappeared
> > /dev/md0
> > Wrong-Level
> > 
> > The RAID seems to be working well. Any pointer on what does this
> > mean ?
> 
>  From  "man mdadm"  (if you know where to look)
> 
>        Follow or Monitor
>               Monitor  one  or  more  md devices and act on any state changes.
>               This is only meaningful for raid1, 4, 5, 6 or  multipath  arrays
>               as  only  these  have  interesting state.  raid0 or linear never
>               have missing, spare, or failed drives, so there  is  nothing  to
>               monitor.
> 
> You are presumably trying to monitor a raid0 (which isn't meaningful)
> and mdadm is telling you (in its own idiosyncratic way) that it isn't
> going to monitor it.
> 

Thank you very much !! One less mistery in my life ;)

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Limited Edition 2005) for i586
Linux 2.6.11-jam14 (gcc 3.4.3 (Mandrakelinux 10.2 3.4.3-7mdk)) #3