Hi raidpeople. I have a redhat 5.2 machine with all updates applied
(regular updates and kernel-2.2 update stuff).
I have been having problems using mkraid to make a raid5 array.
I installed the 2.2.3 kernel and applied the latest patch.
I also built and installed an rpm for raidtools 19990309.
I have 4 scsi disks on a scsi bus connected to a symbios ncr53c8xx
controller, each disk is an identical 4.3GB quantum viking2 or some such
drive.
The machine is a dual p2-450 w/ 256MB ram
The first drive (sda) is dedicated to system stuff, the other three
will be the raid array.
I made an /etc/raidtab that looks something like this:
raiddev /dev/md0
raid-level 5
nr-raid-disks 3
nr-spare-disks 0
chunk-size 128
device /dev/sdb1
raid-disk 0
device /dev/sdc1
raid-disk 1
device /dev/sdd1
raid-disk 2
I then run mkraid and it aborts. I have also tried many options with mkraid
such as --force, -c /etc/raidtab, etc.
The raid5 kernel module is loaded and registered as shown in /proc/mdstat
The drives are formatted as one large partition each, but that should be
wiped out when I create and format the raid device if I am correct.
The /dev/md* devices do exist and the drives seem to be working fine.
But when I run mkraid, mkraid /dev/md0, and other variations, it starts to
go and then aborts with no explination.
Another thing I wanted to ask which altho in the FAQ and other docs, seems
to be under contention (different docs say different things, also, the web
raid howto is not up to date with the howto distributed with raidtools):
chunk size/stride size.
For general purpose file serving of mostly files under 100k (which are
reasonably quick anyway) and doing database stuff,
What chunk size should I use?
The docs said 128 is a reasonable value for raid5.
I am planning on making the fs with a 4k block size, then I should use
16 as the -R stride option to mke2fs, correct?
Just checking, any input is appreciated.
I'm mainly concerned with just figuring out how to get the mkraid to work,
the rest I can fiddle with.
Thanks,
Chris
