I originally set up raid-luks-lvm on this machine with debian's installer tool, now I am trying to add another encrypted raid1 device to the existing volume group. I already have the raid device set up and encrypted, that's no problem. Now the linux gazette (http://linuxgazette.net/140/pfeiffer.html) tells me I should run 'pvcreate' on the device in /dev/mapper. However, if I examine my existing physical volumes with 'pvscan' I get the following: iblis:/home/hatta# pvscan PV /dev/dm-0 VG iblis-volumes lvm2 [931.32 GB / 0 free] Total: 1 [931.32 GB] / in use: 1 [931.32 GB] / in no VG: 0 [0 ] Apparently I am using /dev/dm-0 instead of /dev/mapper/md1_crypt. I wondered if these were maybe two names for the same thing, so I checked ls: iblis:/home/hatta# ls -ld /dev/dm-0 /dev/mapper/md1_crypt brw-rw---- 1 root disk 253, 0 2009-08-16 12:02 /dev/dm-0 brw-rw---- 1 root disk 253, 0 2009-08-16 12:02 /dev/mapper/md1_crypt Same major and minor number, if that means anything. Next I ran 'dmcrypt info' on each: iblis:/home/hatta# dmsetup info /dev/dm-0 Device /dev/dm-0 not found Command failed iblis:/home/hatta# dmsetup info /dev/mapper/md1_crypt Name: md1_crypt State: ACTIVE Read Ahead: 256 Tables present: LIVE Open count: 7 Event number: 0 Major, minor: 253, 0 Number of targets: 1 It works on one, and not the other. So they're not the same thing. My new device 'md2_crypt' corresponds to /dev/dm-8, if I am to trust the major/minor numbers. Should I run pvcreate on /dev/dm-8 or /dev/mapper/md2_crypt? And this is a somewhat broader question. If I have two encrypted volumes like this in the same volume group, and I have a partition that spans both physical volumes, what happens when one of those volumes is not yet unlocked? There is a short time during bootup that md1_crypt is unlocked and md2_crypt is not yet unlocked. The boot scripts are definitely doing something with my logical volumes in that period, since I can use a keyfile in /root (which is in a logical volume on md1_crypt) to unlock md2_crypt. This seems dangerous to me, what would happen if I added md2_crypt to that volume group, and extended that filesystem over both physical volumes? Is it possible for my keyfile in /root to end up on md2_crypt and be inaccessible? Suppose I had trouble entering my passphrase 3 times and cryptsetup gave up. What would happen then? Would my system try to mount a logical volume that only half exists? Could that corrupt the filesystem? -- hatta00@fastmail.fm -- http://www.fastmail.fm - A fast, anti-spam email service. _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/