On Thu, Sep 27, 2007 at 02:53:59AM +1000, Michael Chesterton wrote: > > On 26/09/2007, at 10:36 PM, Erik de Castro Lopo wrote: >> Hmm, thats interesting: >> >> /dev/sda3: UUID="2956c339-fa5e-45d9-ab13-e92a9597ab20" SEC_TYPE="ext2" >> TYPE="ext3" >> /dev/sdb3: UUID="2956c339-fa5e-45d9-ab13-e92a9597ab20" SEC_TYPE="ext2" >> TYPE="ext3" >> /dev/md0: UUID="2956c339-fa5e-45d9-ab13-e92a9597ab20" SEC_TYPE="ext2" >> TYPE="ext3" >> /dev/mapper/sdb3: UUID="2956c339-fa5e-45d9-ab13-e92a9597ab20" >> SEC_TYPE="ext2" TYPE="ext3" >> /dev/mapper/sda3: UUID="2956c339-fa5e-45d9-ab13-e92a9597ab20" >> SEC_TYPE="ext2" TYPE="ext3" >> >> The two disk partitions that make up md0 have the same UUID as md0 >> which matches whats in /etc/fstab. The UUID in mdadm.conf is nowhere to >> be found. > > Here's another command to try > > mdadm --examine --scan This should look at all the valid places md is allowed to look as defined by /etc/mdadm.conf and scan for valid md devices.
using blkid looks at all valid block devices and tries to read the ext2/3 (or other valid fs) info. if md0 was made up of a raid5 set the member disks would not have the same uuid as the fs placed on them. To sum up, md uses uuid's which are different to uuid's used by ext2/3. Blkid works on fs uuids. mdadm uses md uuid's you have stumbled on a attribute or raid1 devices be plain mirrors > > I haven't used software raid for a few years, since before udev and uuid. > Guess I'll > wait for other replies to see how it works :) > > > -- > SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ > Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html >
signature.asc
Description: Digital signature
-- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html