On 11/26/2020 05:27 PM, Leon Fauster via CentOS wrote:
> Am 26.11.20 um 20:10 schrieb H:
>> Running CentOS 7 I have a previously combined backup of a disk with three partitions using dd. I now need to restore one single file from this backup and after perusing the internet, specifically https://unix.stackexchange.com/questions/31669/is-it-possible-to-mount-a-gzip-compressed-dd-image-on-the-fly, I have done the following:
>>
>> - installed squashfs-tools
>>
>> - installed kpartx
>>
>> - made a squash image of the dd backup and mounted it
>>
>> - used kpartx to create devices for the three partitions under /dev/mapper/loopNpP
>>
>> - I can now mount the first partition, which is the EFI partition, and access it
>>
>> - the second partition, the boot partition, fails to mount since it has the same UUID as the disk I am using in the computer, and of which it is an earlier dd backup. Since I am not interested in the boot partition - at least not right now - I moved on.
>>
>> - I am, however, interested in the third partition which is LUKS encrypted. Running 'cryptsetup luksOpen /dev/sda3 my_encrypted_volume' I can decrypt it with the password
>>
>> - trying to mount the decrypted version with 'mount /dev/mapper/my_encrypted_volume /media/my_device' results in a failure message 'mount: unknown filesystem type 'LVM2_member'
>>
>> - another website, https://askubuntu.com/questions/766048/mount-unknown-filesystem-type-lvm2-member, suggests I could run vgdisplay to get the UUID and then rename it using vgrename
>>
>> But, vgdisplay shows only one vg and I am afraid to rename the VG UUID shown by vgdisplay since it might refer to the VG currently in use...
>>
>> Does anyone have any insight or suggestions into the above and how to proceed while being absolutely certain I will not be messing up the running part of the system?
>>
>
> IIRC: Activate the LVM via: vgchange -a y
>
> and mount the logical volume (LV).
>
> LV can be listed with lvs. The device nodes are under /dev/mapper ...
>
> --
> Leon
>
>
>
>
>
> _______________________________________________
> CentOS mailing list
> CentOS@xxxxxxxxxx
> https://lists.centos.org/mailman/listinfo/centos
OK, I am looking at https://www.cyberciti.biz/faq/linux-mount-an-lvm-volume-partition-command/. A couple of follow-up questions:
- Would activating the LVM with 'vgchange -a y' make any changes, or create any potential issues, with the system already running?
- How do I know that the output from 'vgdisplay' refers to this 'new' VG and not VGs on the running system?
- To mount the VG, I would have to run:
-- 'vgscan'
-- make directory for mounting
-- 'mount...' to mount the VG
Is that correct? And it would not create any issues with the running system?
Thank you in advance.
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
https://lists.centos.org/mailman/listinfo/centos
