RE: [cobalt-users] Raid problems on a RAQ4i with staqware

[Clive Harper <CHarper@xxxxxxxxxxxx>]

I did some more digging and found out that the version of
software RAID running on the RAQ4i is called 0.90 RAID layer.

Reading through the HOW-TO file, it appears that the errors we
are having with the RAQ4i are to do with 'The Perisistant Superblock'
this is a snip from the HOW-TO:

<snip>
Back in ``The Good Old Days'' (TM), the raidtools would read your
/etc/raidtab file, and then initialize the array. However, this would
require that the filesystem on which /etc/raidtab resided was mounted.
This is unfortunate if you want to boot on a RAID. 

Also, the old approach led to complications when mounting filesystems
on RAID devices. They could not be put in the /etc/fstab file as usual,
but would have to be mounted from the init-scripts. 

The persistent superblocks solve these problems. When an array is
initialized with the persistent-superblock option in the /etc/raidtab
file, a special superblock is written in the beginning of all disks
participating in the array. This allows the kernel to read the
configuration of RAID devices directly from the disks involved,
instead of reading from some configuration file that may not be
available at all times. 

You should however still maintain a consistent /etc/raidtab file,
since you may need this file for later reconstruction of the array
</snip>

It appears that the RAQ4i on statup cannot read the Persistant
Superblock (PS) on some of the disks and therefore removes and re-creates
the PS on all drives connected to the array.

As we are running Staqware I guess that the Staqware active RAQ is using the
standby RAQ just like a second hdd for RAID 1.

The problem is I do not know whether a Staqware cluster should operate
like this or whether there is a problem in the configuration. Has anyone
else configured a Staqware cluster and if so do you get the same errors on
restarting the Active RAQ ?

This is taken from my /var/dmesg file (Sorry for the long post).

md: disabled device [dev 2b:01], could not read superblock.
md: could not read [dev 2b:01]'s sb, not importing!
could not import [dev 2b:01], trying to run array nevertheless.
autorun ...
considering hda1 ...
  adding hda1 ...
created md1
bind<hda1,1>
running: <hda1>
now!
hda1's event counter: 00000023
md1: former device [dev 2b:01] is unavailable, removing from array!
md1: max total readahead window set to 128k
md1: 1 data-disks, max readahead per data-disk: 128k
raid1: device hda1 operational as mirror 0
raid1: md1, not all disks are operational -- trying to recover array
raid1: raid set md1 active with 1 out of 2 mirrors
md: updating md1 RAID superblock on device
hda1 [events: 00000024](write) hda1's sb offset: 768000
md: recovery thread got woken up ...
md: recovery thread finished ...
.
... autorun DONE.
(read) hda3's sb offset: 205056 [events: 00000026]
(read) [dev 2b:03]'s sb offset: 2097024<3>md: disabled device [dev 2b:03],
could
 not read superblock.
md: could not read [dev 2b:03]'s sb, not importing!
could not import [dev 2b:03], trying to run array nevertheless.
autorun ...
considering hda3 ...
  adding hda3 ...
created md3
bind<hda3,1>
running: <hda3>
now!
hda3's event counter: 00000026
md3: former device [dev 2b:03] is unavailable, removing from array!
md3: max total readahead window set to 128k
md3: 1 data-disks, max readahead per data-disk: 128k
raid1: device hda3 operational as mirror 0
raid1: md3, not all disks are operational -- trying to recover array
raid1: raid set md3 active with 1 out of 2 mirrors
md: updating md3 RAID superblock on device
hda3 [events: 00000027](write) hda3's sb offset: 205056
md: recovery thread got woken up ...
md: recovery thread finished ...
.
... autorun DONE.
(read) hda4's sb offset: 18415552 [events: 00000034]
(read) [dev 2b:04]'s sb offset: 2097024<3>md: disabled device [dev 2b:04],
could
 not read superblock.
md: could not read [dev 2b:04]'s sb, not importing!
could not import [dev 2b:04], trying to run array nevertheless.
autorun ...
considering hda4 ...
  adding hda4 ...
created md4
bind<hda4,1>
running: <hda4>
now!
hda4's event counter: 00000034
md4: former device [dev 2b:04] is unavailable, removing from array!
md4: max total readahead window set to 128k
md4: 1 data-disks, max readahead per data-disk: 128k
raid1: device hda4 operational as mirror 0
raid1: md4, not all disks are operational -- trying to recover array
raid1: raid set md4 active with 1 out of 2 mirrors
md: updating md4 RAID superblock on device
hda4 [events: 00000035](write) hda4's sb offset: 18415552
md: recovery thread got woken up ...
md: recovery thread finished ...
.
... autorun DONE.
trying to remove [dev 2b:01] from md1 ... 
trying to remove [dev 2b:03] from md3 ... 
trying to remove [dev 2b:04] from md4 ...