Hi linux raid gurus,
we're using RAID on our system for 1 1/2 year and everything
works very well (slackware 3.4, linux 2.1.128, raidtools 0.42).
(Except for some trouble with e2fsck on our RAID-5 Array. The server
hangs, and we have to load a very old kernel and use the mdtools in
the ramdisk image to check the raid array and do the fsck)
Due to a general system update we want to install a new linux
distribution (Slackware 4.0). For that reason we also want to update
the RAID- Tools since we saw, that the new release has some nice
features which allows to autodetect the raid devices from the kernel
level (no extra init-files ?).
Right now we boot from an initrd ramdisk image which activates our
raid sets and switches the root filesystem to a Mirrored RAID-1
partition. User data is placed on a RAID-5 array, temporary and
static data on RAID-0.
We downloaded kernel 2.2.10, the raid patch for this kernel and the
actual raidtools. Raid stuff comes from
ftp.fi.kernel.org/pub/linux/deamons/raid/alpha.
We managed to migrate the RAID-1 partition with the
--upgrade option of mkraid. This does not seem to work with our RAID-
0 sets. And we did not try this with the RAID-5 partitions, because
we have about 20GB of User data there which should not be lost.
Is there any problem using the new Kernel and RAID stuff with the old
RAID-5 set?
It ist possible to start the RAID-0 Arrays using raid0run!
Is there any chance to migrate the RAID-0 arrays?
Thanks in advance.
Oliver
PS: Here our old setupfiles :
/etc/mdtab :
##############
# mdtab entry for /dev/md0
/dev/md0 raid1,4k,0,0e141176 /dev/sdb1 /dev/sdc1
# mdtab entry for /dev/md1
/dev/md1 raid0,4k,0,95eab268 /dev/sda3 /dev/sdb3 /dev/sdc3
/dev/sdd3 /dev/sde3
# mdtab entry for /dev/md2
/dev/md2 raid0,4k,0,2760ae90 /dev/sda5 /dev/sdb5 /dev/sdc5
/dev/sdd5 /dev/sde5
# mdtab entry for /dev/md3
/dev/md3 raid5,4k,0,e6b6c9c6 /dev/sda6 /dev/sdb6 /dev/sdc6
/dev/sdd6 /dev/sde6
##############
Here two files used to fix Arrays :
for the mirrored Array
################################
raiddev /dev/md0
raid-level 1
nr-raid-disks 2
nr-spare-disks 0
device /dev/sdb1
raid-disk 0
device /dev/sdc1
raid-disk 1
#################################
Our raid 5 Array
#################################
# ITA raid-5 configuration
raiddev /dev/md3
raid-level 5
nr-raid-disks 5
chunk-size 32
# Parity placement algorithm
#parity-algorithm left-asymmetric
parity-algorithm left-symmetric
#parity-algorithm right-asymmetric
#parity-algorithm right-symmetric
# Spare disks for hot reconstruction
nr-spare-disks 0
device /dev/sda6
raid-disk 0
device /dev/sdb6
raid-disk 1
device /dev/sdc6
raid-disk 2
device /dev/sdd6
raid-disk 3
device /dev/sde6
raid-disk 4
################################
Here ist what we tried as /etc/raidtab with the new tools
######################################################################
raiddev /dev/md0
raid-level 1
nr-raid-disks 2
nr-spare-disks 0
# Next just because needed when starting mkraid
chunk-size 4
# Hope, that it will run ... it did!
persistent-superblock 1
device /dev/sdb1
raid-disk 0
device /dev/sdc1
raid-disk 1
raiddev /dev/md1
raid-level 0
nr-raid-disks 5
# Next just because needed when starting mkraid
chunk-size 4k
# Hope, that it will run ... did not :-(
# persistent-superblock 1
device /dev/sda3
raid-disk 0
device /dev/sdb3
raid-disk 1
device /dev/sdc3
raid-disk 2
device /dev/sdd3
raid-disk 3
device /dev/sde3
raid-disk 4
raiddev /dev/md2
raid-level 0
nr-raid-disks 5
# Next just because needed when starting mkraid
chunk-size 4k
# Hope, that it will run ...
# persistent-superblock 1
device /dev/sda5
raid-disk 0
device /dev/sdb5
raid-disk 1
device /dev/sdc5
raid-disk 2
device /dev/sdd5
raid-disk 3
device /dev/sde5
raid-disk 4
###################################
------
Oliver Schmitz, Arbeitsgebiet : Raumakustik, Netzwerkadministration
Institut fuer Technische Akustik der RWTH Aachen
http://www.akustik.rwth-aachen.de/Ww/deutsch/ita/personal/osc.html
http://www.akustik.rwth-aachen.de/cgi-bin/rwth_security
