i have been trying to install software raid on two systems for the past
several days. i am planning to document the experience and submit a newer
version of the current howto (since there were no complaints at this
suggestion)
however, i have had extreme problems with the newer versions.
the setup:
PII-350, 128M, two IBM 8.4 gig IDE drives.
i want to have:
7 different raid1 or raid0 partitions of various sizes. while it would be
more efficient to have more disks and put say, 3 partitions on one pair of
drives, and 4 on another pair, i think this is a realistic setup.
i have:
partitioned both disks into 8 partitions. (7 raid plus 1 for booting).
each disk is on a separate channel in the on-mboard controller, no other
ide/atapi devices. i installed RH5.2 to some of the partitions on hda.
download fresh 2.0.36 tarball, patch with raid0145-19990108, and install
the latest raidtools. upgrade all errata rpms (like a good little RH
punk). compile and install new kernel with raid support NOT as a module.
kernel boots, runs fine with plain disk partitions.
the problem:
mkraid -f /dev/md0 complains about active inodes. guess what, this disk is
new, and unmounted. no active inodes are there. even a
dd if=/dev/zero of=/dev/sdc5 bs=512k count=205
which will take care of any factory data on the disk does not help. a
second attempt to mkraid on the same device complains that it is already
in use, but i never got it started! i have also used the older 2.0.36
patches, and the cooresponding raidtools, all of them do this.
the fix:
i down graded to 2.0.35 and raid0145-19981110 and raidtools-19981105.
this is capable of mkraid, autostart, etc. i have this in production
already though, and i was hoping to use the newer stuff (i will try
2.2.0preX later). i ran mkraid with /dev/md0 consisting of just /dev/hdc5,
then copied everything from my old root (/dev/hda5) to /dev/md0.
did the same for all other partitions. system is now running entirely off
of single-disk raid1 partitions.
i want to use 2.0.36 for the ethernet drivers, etc, but would rather not
forward-port older patches from 2.0.35
problem two:
i have installed rh into several of the raid halfs (rather than use a
sacrificial partition as i had planned originally).
raidhotadd /dev/md0 /dev/hda5
does say that it adds the partition to the array. however, on reboot,
kernel reports that /dev/hda5 is unavailable and unbinds it from array.
i can re-add it, but it does not stay after re-boot.
i have tried raidhotadd with the raidtab updated to include the new
partition, and with it in the old config. it does not seem to matter!
how do i get that to stay?
i will be making html versions of my new howto available early next week,
after i have time to play with 2.2.0pre (hopefully) i will request
comments at that time as well, but if you guys have any hints you want me
to include email them please. i intend to replace current howto.
thanks mingo and company.
allan noah
sysadmin pfeiffer u.
"so don't tell us it can't be done, putting down what you don't know.
money isn't our god, integrity will free our souls" - Max Cavalera
