I just set up my box to use software RAID 1 accross two SATA II drives. More of a question than a problem:

When I set up the RAID in the installer, I told it to set up the drives like so (the partition sizes are close):

/dev/sda2 RAID device 150 MB
/dev/sda3 RAID device 107.5 GB
/dev/sda1 Windows ~ 40 GB

/dev/sdb1 RAID device 150 MB
/dev/sdb2 RAID device 107.5 GB
/dev/sdb3 SWAP 16GB

/dev/md0 ext3 /boot 150 MB RAID 1 sda2, sdb1
/dev/md1 ext3 / 107.5 GB RAID 1 sda3, sdb2

Here's the confusing part:

when I boot up the system and run mdadm --detail /dev/md1, it turns out that only one partition is 107.5 GB, the other is something like 100 GB, and md1 is 104 GB (the avarige size of the RAID partitions). Is this bad? I only have experience with RAID on RHEL boxes, and the partitions there were always the same size.

edit: the same thing happened to /dev/md0, but it's only off by a few MB. I also installed the Windows partition before linux, and am upgrading from FC4.

Even if this isn't a big problem, is it possible, and if so, how do I make the partitions the same size, apart from blowing away sdb, and re-writing all of the data?

thanks!

The problem may come from different cluster size, because it looks like one of your disks is bigger than the other. You can check if this is the case and see exact number of clusters allocated for each partition by running:
Then again, you might try to use
to resize your (unmounted) partitions, preferably using a LiveCD of some sort.

the disks are exactly the same size, just one of them has some unpartitioned space.

thanks, I think I'll try cfdisk.

the confusing thing is that I used FC4 on this exact same setup, but the partitions came out to be the same size.

Better yet, try using "gparted" or "qtparted" instead. They are much more user-friendly and work decently well (I used "gparted" several times with great success). I know 100% that Ubuntu LiveCD contains "gparted", while Kubuntu LiveCD should probably contain "qtparted".

Hope this helps.

yep. I used gparted. everything is now working. thanks.