Problem with RAID1 on kernel 2.4
Hi All
I have just spent many hours trying to setup raid1 on a machine with
an hpt366/htp370 ide chipset.
The machine has 3 ide hard drives as raid 1 + 1 hot spare, and a
CD Rom, each device has its own IDE interface.
The chipset has 4 ide ports and is supported on kernel 2.4. The
chipset has raid "features" but as I understand it these are
implemented via a software disk driver, typically on Windows.
There are patches for kernel 2.2 and some weird drivers from the
manufactures web site which I think do the same under Linux.
However kernel 2.4 has native support for the chipset and the other
development seems to have stopped. With 2.4 running I was
presented with /dev/hda, dev/hdc, /dev/hde, /dev/hdg for the drives.
I installed linux raid1 for raid support.
I installed a standard debian 2.4.17 kernel and just enough
packages out of woody to get it going. The rest is potato. After a
long night I think have got it all going. However there are some
areas that I am still not sure of:
1) The initrd is massive about 3mB, I hope that means I will always
have all the modules I will ever need at boot time, and I assume
the RAM is freed up by the time the system is running. I
increased the size of my boot partition to 15 mB, but otherwise
this is not really a problem.
Notwithstanding the above, I put a long list of modules in both
/etc/modules and /etc/mkinitrd/modules. (ide stuff, md, raid1,
ext2 ext3 etc), I am not sure how much of this was necessary.
2) Then I had endless problems with raid1. It seems that the
"failed-disk" directive in /etc/raidtab does not work. I think
it has something to do with devfs - which is compiled into the
standard "woody" 2.4 kernel.
proc/mdstat shows the drives with their devfs names not the old
/dev/hd.. names.
While all the other directives seemed to work, using standard
/dev/hd.. names and I could build the raid, if I did a raidstop,
followed by raidstart, it would not start again. Rather it gave
me an error relating to the partition listed as "failed-disk".
The only way to get it running again was with a mkraid
--really-force option.
I tried installing debian's devfsd package but did not solve
the problem. Maybe there is some clever customization required
to make it work.
Putting the full devfs names into /etc/raidtab did not work.
Maybe I did not have everything setup correctly or I got the
names wrong. I could not find any devfs devices in the /dev
directory.
After lots of manipulation I managed to build a working system
from a single disk to raid1 on all partitions, without relying
on failed-disk, and it all seems to be working now.
I am not sure how much is related to the chipset, or whether this is a
known issue with kernel 2.4. In hindsight, I should have compiled a
new kernel without initrd or devfs and made all the raid and ide
modules built in. I actually tried this but after two or three
compilations without getting a kernel with the right configuration, I
thought doing it the other way might be faster.
Has anybody else been down this road yet?
Ian
---------------------------------------------------------------------
Ian Forbes ZSD
http://www.zsd.co.za
Office: +27 21 683-1388 Fax: +27 21 674-1106
Snail Mail: P.O. Box 46827, Glosderry, 7702, South Africa
---------------------------------------------------------------------
Reply to: