Access Old Home Directory - USB enclosure - LVM

[Robert L Cochran]

Jim Cornette wrote:

> Robert L Cochran wrote:
>
>> I searched the archives for whatever  I had to do in order to get the 
>> lvm activated. Here is one posting that I made:
>>
>>>
>>> https://www.redhat.com/archives/fedora-list/2005-April/msg01943.html
>>>
>>> From an earlier posting someone suggested to run the following 
>>> commands to activate and later deactivate LVM volumes in rescue 
>>> mode. I used these commands on an external USB drive to get at data 
>>> from a previous installation and it worked. You might be able to get 
>>> at your data in this way.
>>> Jim
>>>
>>> Excerpt from earlier help.
>>> Once booted into text-mode rescue, invoke the following commands:
>>>
>>>
>>> lvm lvscan
>>> lvm vgchange -ay
>>>
>>>
>>> This will scan for all LVM volumes and then will make them active 
>>> and accessible.
>>>
>>> lvm vgchange -an
>>>
>>> will deactivate them all.
>>> end Excerpt:
>>>
>>> Basically, the LVM volumes on the hard drive from an earlier install 
>>> was labeled / for the main partition and this label being the same 
>>> as my non-lvm clean install was also labeled /. When the kernel 
>>> booted and the saw the same label, it ignored the LVM which 
>>> contained the / and swap lvm content.
>>> To access the partition, I ran the lvscan and vgchange commands. I 
>>> then had to make a mountpoint under /mnt to mount the LVM partition.
>>> I believe I got the information as /dev-mapper/volgroup00/<whatever> 
>>> --- Sorry, I forgot what it is called, I no longer use LVM.
>>> I took that information of where the volume was and used mount 
>>> /dev-mapper/volgroup00/<whatever> /mnt/olddrive and was able to 
>>> access all the content from the LVM after mounting it.  I 
>>> transferred all of my desired information from the drive and never 
>>> used it since.
>>>
>>> There might be discussions in march of this year or close to that 
>>> time frame in the archives. The helpful person has not posted 
>>> recently to my knowledge but knew a lot about dealing with LVMs.
>>>
>>> All of your swap partitions and other filesystem dvisions are all 
>>> contained in the LVM. The only partitions you should have are the 
>>> one for windows, the /boot partition and the third partition should 
>>> be where all of the LVM "partitions" or slices are kept. If you ran 
>>> fdisk on the /dev/sdb device, you should have three partitions. 
>>> Without dev-mapper, it does not show.
>>>
>>> Good luck! It is possible, I just cannot remember the exact method 
>>> that I used to get at the LVM.
>>>
>>> Jim
>>>
>> Thanks for the detailed help, Jim! I'll give this a try later this 
>> morning after I recover from the New Year's party.
>>
>> Bob
>>
>>
>
> It would probably be safer to wait until then. I hande over the 
> computer to Linux tots for the evening and they stayed occupied with 
> ppracer, neverball, super tux and the like. None of them were 
> interested in accessing files on a drive configured with LVM.
>
> Better luck in 2006
>
> Jim
>
I'd like to follow up on this. Here is what I did.

1. Booted machine in rescue mode, using my install DVD, with the 
external USB drive containing my other FC4 system  plugged in.
2. Executed 'chroot /mnt/sysimage'.
3. Ran 'lvm lvscan' as suggested. I got this output.

ACTIVE 'dev/VolGroup00/LogVol00' [370.53 GB] inherit
ACTIVE 'dev/VolGroup00/LogVol01' [1.94 GB] inherit

The above logical volumes seem to reference my 400 Gb hard drive in my 
new, upgraded system, not the 60 Gb drive which is connected by USB.

I then unplugged the USB cable for my 60 Gb drive and re-plugged it in. 
Executing 'lvm lvscan' then got me this output:

/dev/sdb1: open failed: no such device or address
/dev/sdb2: open failed: no such device or address
/dev/sdb3: open failed: no such device or address

ACTIVE 'dev/VolGroup00/LogVol00' [370.53 GB] inherit
ACTIVE 'dev/VolGroup00/LogVol01' [1.94 GB] inherit

Question: should I have manually mounted the partitions before issuing 
'lvm lvscan'?

************ (Removed rescue CD, boot back into Fedora Core 4 on new 
system) ************

I then read the entire LVM how-to for lvm2 on tldp.org. It doesn't offer 
practical advice for this situation -- rescuing data from an older 
lvm-based system.

I also read 'man lvm', with no better results.

I then checked Bugzilla. There are 124 (or is it 125?) bugs listed for LVM.

It is looking more and more like I'll need to take out my 400 Gb drive 
and substitute my 60 Gb drive/120 Gb drive, and boot into that system, 
all to recover a little more data. Perhaps I need to quit using LVM.

Thanks

Bob Cochran