[linux-lvm] Lost logical volume?

[Peter Smith]

Tom+Dale wrote:

> Greetings.
> I am hoping that some LVM experts can help me out. I have a partial 
> volume group that spans two drives and I would like to recover the 
> logical volume that was on it so that the data is accessible. The 
> group (VolGroup00) was originally set up spanning part of one drive 
> and all of the other drive (both IDE). The group was entirely applied 
> to a single logical volume (LogVol00) to be mounted as /video. This 
> was working until I tried to make some changes and I fear that I may 
> have lost the data. I cannot seem to resolve this problem anywhere 
> else. I have spent almost two weeks searching for clues and asking for 
> help in other forums, but I do not yet have a solution. I hope to 
> provide all of the useful information below.
> *History*
> I am relatively new to linux, having built my own PVR using Fedora and 
> MythTV during the last year. I have relied heavily upon HowTos and 
> guides written by other users. One of the guides that I followed 
> instructed me to set up XFS using LVM which would allow me to span 
> multiple hard disks. Recently, I added a new SATA drive to my MythTV 
> system. The new drive was designated as /dev/sda. It appeared to add 
> into the existing volume group without any problem, though I did not 
> get it to the point where the space was accessible. I planned to 
> further research that problem; however, the new hard drive failed 
> before I got that far. Here’s what things looked like after removing 
> the drive:
> [root[at]mythserver ~]# pvdisplay
> Couldn't find device with uuid 'fxlccO-4li0-nmyD-9avZ-Vc60-GGWX-jUhqOv'.
> Couldn't find device with uuid 'fxlccO-4li0-nmyD-9avZ-Vc60-GGWX-jUhqOv'.
> --- Physical volume ---
> PV Name /dev/hda5
> VG Name VolGroup00
> PV Size 66.12 GB / not usable 0
> Allocatable yes (but full)
> PE Size (KByte) 4096
> Total PE 16926
> Free PE 0
> Allocated PE 16926
> PV UUID 317l2C-oay1-TWFG-5NTX-XJS3-vLal-Xh5bBL
>
> --- Physical volume ---
> PV Name /dev/hdb
> VG Name VolGroup00
> PV Size 298.09 GB / not usable 0
> Allocatable yes (but full)
> PE Size (KByte) 4096
> Total PE 76311
> Free PE 0
> Allocated PE 76311
> PV UUID nfLxS1-0u3t-5Zr9-57iu-1oZe-Bkkd-75SERQ
>
> --- Physical volume ---
> PV Name unknown device
> VG Name VolGroup00
> PV Size 232.88 GB / not usable 0
> Allocatable yes
> PE Size (KByte) 4096
> Total PE 59617
> Free PE 225
> Allocated PE 59392
> PV UUID fxlccO-4li0-nmyD-9avZ-Vc60-GGWX-jUhqOv
>
>
Tom. I'm sorry that not too many people have looked into this with you.

First, what were the results of the "vgreduce --removemissing 
VolGroup00" command? I'm generating a theory here. That VolGroup00 had a 
single LV, LogVol00, and the disks /dev/hda5 and /dev/hdb. Then--I'm 
guessing here--you did a "pvcreate /dev/sda" .. And followed that with a 
"vgextend VolGroup00 /dev/sda" .. Then perhaps did you do a "lvextend -l 
<some number> /dev/VolGroup00 /dev/sda"? After that, at some point, 
/dev/sda went dead. Am I close? Could you recount to us what steps you 
took to "expand" the VG? I realize you may have been asleep, but this 
data is crucial. When I do any LVM work I typically record all my input 
and output in a text editor and save it or print it out for safety..

So, the questions are:
1) Was that LV the ONLY LV in the VG?
2) You did try to expand the LV to include /dev/sda?
3) Did you use any GUI to do this? Or did you rely on the command line?

Peter