Mdadm Issue

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CentOS 5 Comments

Just rebuilt a C6 box last week as C7. Four drives, and sda and sdb for root, with RAID-1 and luks encryption.

Layout:
lsblk NAME MAJ:MIN RM SIZE RO TYPE
MOUNTPOINT
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 200M 0 part
/boot/efi
├─sda2 8:2 0 1G 0 part /boot
├─sda3 8:3 0 500.1G 0 part
│ └─md127 9:127 0 500G 0 raid1
│ └─luks-5e007234-cd4c-47c6-b305-734f353a4405
253:0 0 500G 0 crypt /
├─sda4 8:4 0 4G 0 part
│ └─md126 9:126 0 4G 0 raid1
│ └─luks-9dd9aacc-e702-43d9-97c2-e7e954619886
253:1 0 4G 0 crypt [SWAP]
└─sda5 8:5 0 426.2G 0 part
└─md125 9:125 0 426.1G 0 raid1
sdb 8:16 0 931.5G 0 disk
├─sdb1 8:17 0 500.1G 0 part
│ └─md127 9:127 0 500G 0 raid1
│ └─luks-5e007234-cd4c-47c6-b305-734f353a4405
253:0 0 500G 0 crypt /
├─sdb2 8:18 0 4G 0 part
│ └─md126 9:126 0 4G 0 raid1
│ └─luks-9dd9aacc-e702-43d9-97c2-e7e954619886
253:1 0 4G 0 crypt [SWAP]
└─sdb3 8:19 0 426.2G 0 part
└─md125 9:125 0 426.1G 0 raid1

The problem is md125. System gagged on bringing it up when I rebooted, until I commented it out of fstab.

Now, cryptsetup gives me the same UUID as I have in /etc/mdadm.conf. The entry in /etc/crypttab looks identical to the RAIDs for root and swap, but nope.

I was able to d an mdadm –assemble -u $(UUID from mdadm.conf), and then a cryptopen luks… but never got anything in /dev/mapper.

I’m still fighting – any thoughts? (No, I can’t reboot again, like I did this morning, it’s now serving four important home directories from another pair of drives with RAID 1.)

mark

5 thoughts on - Mdadm Issue

  • Can you post those files somewhere?  I’m confused by the idea that cryptsetup is involved in or using the same UUID as an MD RAID device.

  • Gordon Messmer wrote:
    ARRAY /dev/md/root metadata=1.2 name=:root UUID=7dea42fa:c9ef035d:0a6bada5:3ba5c21f ARRAY /dev/md/export_1 metadata=1.2 name=:export_1
    UUID=637ef224:91b445d8:69d48980:adc8bc70

    and, from /etc/fstab, the same drives
    /dev/mapper/luks-5e007234-cd4c-47c6-b305-734f353a4405 /
    xfs defaults,x-systemd.device-timeout=0 0 0
    /dev/mapper/luks-3da4ae38-b78a-4fb4-9c2d-b029a9b16378 /export/1 xfs defaults 0 0

    excerpt the last luks doesn’t exist. They *both* say UUID, so it’s *so*
    simple to understand (NOT). I got the mdraid UUID from mdadm –examine
    –scan.

    mark

    mark

  • I still don’t understand how this relates to md125.  I don’t see it referenced in mdadm.conf.  It sounds like you see it in the output from lsblk, but only because you manually assembled it.  Do you expect there to be a luks volume there?

  • mark, have you checked for luks info on md125?  Does it have a matching entry in /etc/crypttab?