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@centos.org > 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@centos.org https://lists.centos.org/mailman/listinfo/centos
