On Thursday 28 May 2015 19:51:24 Rich Freeman wrote: > On Thu, May 28, 2015 at 1:03 PM, Peter Humphrey <pe...@prh.myzen.co.uk> wrote: > > I've found blkid, which tells me the UUIDs of my various devices, thus: > > > > # blkid /dev/md7 > > /dev/md7: UUID="ycGMf9-hEP2-tjT4-AtkJ-n8RI-pZ44-RqvlEY" > > TYPE="LVM2_member" > > Just keep in mind that the UUID that goes into mdadm.conf might not be > the same UUID returned by blkid. I'm honestly not certain either way. > You can get the mdadm ID from mdadm --detail --scan.
Good grief! When is a UUID not a UUID? Or, how can one device have more than one UUID? > > Two odd things: > > 1. /dev/md7 is the physical volume in which logical volumes are > > defined, so I'm surprised to see TYPE="LVM2_member". > > I'm pretty sure this is fine. It recognizes it as an LVM pv, so that > makes it an LVM2 member. If you say so. It still smells a bit to me. > > 2. There is no entry corresponding to /dev/md7 under > > /dev/disk/by-uuid, though /dev/md1 and /dev/md5 do have entries there > > [1]. > > udev may be configured to not create uuid symlinks for LVM pvs (since > you wouldn't directly mount them anyway). The others contain > filesystems and do get symlinks. > > > What should I be doing about this? > > I'd probably just edit your mdadm.conf to be more liberal with > scanning, and add the arrays output by mdadm --detail --scan to your > config file. That alone may make your problems go away, and it should > be pretty harmless. OK, so this is what I have at present. I haven't booted with it yet to test it - I'll do that in the morning: DEVICE /dev/sd[abcde][123456789] ARRAY /dev/md1 UUID=ea156c7f:183ca28e:c44c77eb:7ee19756 ARRAY /dev/md5 UUID=e7640378:966a5b3a:c44c77eb:7ee19756 ARRAY /dev/md7 UUID=c2d056c4:9118021f:ad73c633:b38fa97c > Nothing about what you've written here concerns me. Well, let us be thankful for small mercies :-) -- Rgds Peter
