I am trying to re-setup my fake-raid (RAID1) volume with LVM2 like setup previously. I had been using dmraid on a Lenny installation which gave me (from memory) a block device like /dev/mapper/isw_xxxxxxxxxxx_ and also a /dev/One1TB, but have discovered that the mdadm has replaced the older and believed to be obsolete dmraid for multiple disk/raid support.
Automatically the fake-raid LVM physical volume does not seem to be set up. I believe my data is safe as I can insert a knoppix live-cd in the system and mount the fake-raid volume (and browse the files). I am planning on perhaps purchasing another at least 1TB drive to backup the data before trying to much fancy stuff with mdadm in fear of loosing the data.
A few commands that might shed more light on the situation:
pvdisplay (showing the /dev/md/[device] not recognized yet by LVM2, note sdc another single drive with LVM)
--- Physical volume ---
PV Name /dev/sdc7
VG Name XENSTORE-VG
PV Size 46.56 GiB / not usable 2.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 11920
Free PE 0
Allocated PE 11920
PV UUID wRa8xM-lcGZ-GwLX-F6bA-YiCj-c9e1-eMpPdL
cat /proc/mdstat (showing what mdadm shows/discovers)
md127 : inactive sda(S) sdb(S)
4514 blocks super external:imsm
ls -l /dev/md/imsm0 (showing contents of /dev/md/* [currently only one file/link ])
lrwxrwxrwx 1 root root 8 Nov 7 08:07 /dev/md/imsm0 -> ../md127
ls -l /dev/md127 (showing the block device)
brw-rw---- 1 root disk 9, 127 Nov 7 08:07 /dev/md127
It looks like I can not even access the md device the system created on boot.
Does anyone have a guide or tips to migrating from the older dmraid to mdadm for fake-raid?
fdisk -uc /dev/md127 (showing the block device is inaccessible)
Unable to read /dev/md127
dmesg (pieces of dmesg/booting)
[ 4.214092] device-mapper: uevent: version 1.0.3
[ 4.214495] device-mapper: ioctl: 4.15.0-ioctl (2009-04-01) initialised: email@example.com
[ 5.509386] udev: starting version 163
[ 7.181418] md: md127 stopped.
[ 7.183088] md: bind<sdb>
[ 7.183179] md: bind<sda>
update-initramfs -u (Perhaps the most interesting error of them all, I can confirm this occurs with a few different kernels)
update-initramfs: Generating /boot/initrd.img-2.6.32-5-xen-amd64
mdadm: cannot open /dev/md/OneTB-RAID1-PV: No such file or directory
Revised my information, inital thread on Debian-users thread at:
Thanks for any ones help :)
- From: Neil Brown <firstname.lastname@example.org>