Hey all... I'm looking for some help figuring out how to shrink a RAID1 device that's mounted as root on a Red Hat system. The device setup is this: Raiddev /dev/md0 Device /dev/hda1 Raid-disk 0 Device /dev/hdb1 Raid-disk 1 Hda and hdb are both 36GB ATA hard drives, and each currently has a partition of about 33GB formatted as Linux RAID autodetect. Each also has a swap partition. What I'd like to do is shrink partition 1 on each disk to around 16GB, and then create a second RAID1, /dev/md1, with a new partition /dev/hda3 and /dev/hdb3 (leaving the swap device alone.) I booted off a rescue disk with mdadm, resize2fs, fdisk, etc, and I was able to shrink /dev/md0 down to 16GB. I then tried to delete /dev/hda1 and /dev/hdb1 using fdisk, and create 2 new equally-sized partitions in the free space created. (/dev/hda1, /dev/hda3, /dev/hdb1, /dev/hdb3, all type Linux RAID Autodetect). Because /dev/hd[ab]1 is larger than /dev/md0, and the starting block of the partitions is the same, the filesystem should remain intact. However, upon rebooting, I ran into a problem. /dev/md0 cannot be mounted because of a problem with the superblocks. I figure that something needs to be done with mdadm to get it to recognize the "new" /dev/hda1 and /dev/hdb1 as /dev/md0 -- but I don't want to do a mdadm --create because that will overwrite the filesystem already on the disks (I think?). Is this something that mdadm --assemble can do? If so, what switches need to be fed to the command? Other suggestions? - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
