LVM / device mapper
 

Hello,
We have been having a nightmare of a time with a crash on one of our file shares.

We finally were able to recover the logical volume group and get the path to return. However it appears its mapping is off.

dmsetup status
vg_flood-sff_share:
vg_os-lv_tmp: 0 10485760 linear
vg_os-lv_usr: 0 20971520 linear
vg_os-lv_var: 0 10485760 linear
vg_os-lv_opt: 0 41943040 linear
vg_os-lv_swap: 0 16777216 linear
vg_os-lv_root: 0 10485760 linear


dm6 I would guess is where /dev/mapper/vg_flood-sff_share needs to be mapped to, as it is the only one without mapping. As you can see dmsetup also shows this logical volume as different than the rest.

I am trying to figure out how to fix the mapping for this so that I can activate the logical volume and get our data back.

Not entirely sure on the question as some details are missing (dm6?).
However, maybe you have to manually create the device mapping?
http://wiki.gentoo.org/wiki/Device-mapper

Yes dm6.

The device manager mapping. LVM has other mapping setup /dm-1 - dm-5. The volume group I am having trouble with appears to have been mapped to dm-6. (vg_flood-ssf_share)

[root@rslxflood5 mapper]# ls -la
total 0
drwxr-xr-x 2 root root 200 Feb 11 15:46 .
drwxr-xr-x 18 root root 5760 Feb 11 15:46 ..
crw-rw---- 1 root root 10, 58 Feb 11 15:11 control
brwxrwxrwx 1 root root 253, 6 Feb 11 15:46 vg_flood-sff_share
lrwxrwxrwx 1 root root 7 Feb 11 15:12 vg_os-lv_opt -> ../dm-5
lrwxrwxrwx 1 root root 7 Feb 11 15:12 vg_os-lv_root -> ../dm-0
lrwxrwxrwx 1 root root 7 Feb 11 15:11 vg_os-lv_swap -> ../dm-1
lrwxrwxrwx 1 root root 7 Feb 11 15:12 vg_os-lv_tmp -> ../dm-4
lrwxrwxrwx 1 root root 7 Feb 11 15:12 vg_os-lv_usr -> ../dm-2
lrwxrwxrwx 1 root root 7 Feb 11 15:12 vg_os-lv_var -> ../dm-3



After the restore in LVM it appears the mapping did not come back.

Here is the volume group

--- Logical volume ---
LV Path /dev/vg_flood/sff_share
LV Name sff_share
VG Name vg_flood
LV UUID NLTNgm-1Zze-o8yS-Di9w-o4bf-7df3-eNNaad
LV Write Access read/write
LV Creation host, time rslxflood5.air-worldwide.com, 2014-07-03 08:22:37 -0400
LV Status suspended
# open 0
LV Size 47.98 TiB
Current LE 12578628
Segments 35
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:6



everything seems to be fine. The only thing is that mapping is off, and I am guessing that is why the LV will not activate.

At this point my guess is I am going to be unable to start the logical volume. It just wont activate, and I was unable to get it to resume using dmsetup resume /dev/vol_grp/lv_00

# dmsetup resume /dev/vg_flood/sff_share
device-mapper: resume ioctl on vg_flood-sff_share failed: Invalid argument
Command failed

adding a little more meat:

dmsetup info /dev/vg_flood/sff_share
Name: vg_flood-sff_share
State: SUSPENDED
Read Ahead: 256
Tables present: None
Open count: 0
Event number: 0
Major, minor: 253, 6
Number of targets: 0
UUID: LVM-aRkAXWK0t1zha48fQgrJP3N2IsWSUirRNLTNgm1Zzeo8ySDi9wo4bf7df3eNNaad

Closing this an moving out of newbie