I need help mounting an lvm2 partition with 14.04 LTS live USB

SOLUTION: I was able to mount the partition and copy the files to another drive!

sudo fuseext2 -o ro -o allow_other /dev/mapper/vg1-lg1 /mnt

was the key. I still have not been able to access the files through nautilus, bit I've been able to copy the important stuff via the terminal.

I'm trying to mount a drive from a seagate central NAS using the 14.04 live USB to make sure the hardware is working before I turn this desktop into my new NAS. I found the partition with gparted - listed as /dev/sdb8, but I can't get it to mount. It has stuff on it (pictures/movies/etc) that I don't want to lose, so I don't want to just wipe it.

So far, I have tried to update/install lvm2 with apt-get - it tells me that is on the newest version. I have entered the UUID in fstab, and give it a mount point. Now when I run sudo mount /dev/sdb8, I get the message "mount: unknown filesystem type lvm2" (I get the same sort of thing when I tried changing the filesystem in fstab to lvm2_member.

I've tried changing a few things around and a re-occurring theme is the error message "missing codepage or helper program, or other error" it mentions a bad superblock on /dev/mapper/vg1-lv1.

If I can, I'll edit this in a moment with some terminal stuff. (Edited)

Hopefully somebody will be able to help me out with this, thank you in advance.

ubuntu@ubuntu:~$ sudo mount /dev/sdb8
mount: unknown filesystem type 'lvm2'

ubuntu@ubuntu:~$ sudo lvs
  LV   VG   Attr      LSize Pool Origin Data%  Move Log Copy%  Convert
  lv1  vg1  -wi-a---- 1.81t

ubuntu@ubuntu:~$ sudo vgdisplay
--- Volume group ---
VG Name               vg1
System ID             
Format                lvm2
Metadata Areas        1
Metadata Sequence No  2
VG Access             read/write
VG Status             resizable
MAX LV                0
Cur LV                1
Open LV               0
Max PV                0
Cur PV                1
Act PV                1
VG Size               1.81 TiB
PE Size               4.00 MiB
Total PE              475641
Alloc PE / Size       475641 / 1.81 TiB
Free  PE / Size       0 / 0   
VG UUID               UXroWv-R8vv-2p4f-CzTc-6fO2-gMRd-cvTsNJ

ubuntu@ubuntu:~$ sudo lvdisplay
  --- Logical volume ---
LV Path                /dev/vg1/lv1
LV Name                lv1
VG Name                vg1
LV UUID                J6GHai-LQW1-kTqF-OkBQ-FaJm-t2cr-AEBbLq
LV Write Access        read/write
LV Creation host, time , 
LV Status              available
# open                 0
LV Size                1.81 TiB
Current LE             475641
Segments               1
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           252:0

ubuntu@ubuntu:~$ sudo lvscan
ACTIVE            '/dev/vg1/lv1' [1.81 TiB] inherit

ubuntu@ubuntu:~$ ls /dev/mapper
control  vg1-lv1

EDIT:

ubuntu@ubuntu:~$ sudo mount /dev/mapper/vg1-lv1 /mnt
mount: wrong fs type, bad option, bad superblock on /dev/mapper/vg1-lv1,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

Output of sudo mount:

ubuntu@ubuntu:~$ sudo mount
/cow on / type overlayfs (rw)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
/dev/sdc1 on /cdrom type vfat (rw,noatime,fmask=0022,dmask=0022,codepage=437,ioc
harset=iso8859-1,shortname=mixed,errors=remount-ro)
/dev/loop0 on /rofs type squashfs (ro,noatime)
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)
systemd on /sys/fs/cgroup/systemd type cgroup(rw,noexec,nosuid,nodev,none,name=systemd)
gvfsd-fuse on /run/user/999/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=ubuntu)

output sudo fdisk -l

ubuntu@ubuntu:~$ sudo fdisk -l

WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn
't     support GPT. Use GNU Parted.


Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1  3907029167  1953514583+  ee  GPT
Partition 1 does not start on physical sector boundary.

Disk /dev/sdb: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00180018

Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *          63   625121279   312560608+   7  HPFS/NTFS/exFAT

Disk /dev/mapper/vg1-lv1: 1995.0 GB, 1994982948864 bytes
255 heads, 63 sectors/track, 242542 cylinders, total 3896451072 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/vg1-lv1 doesn't contain a valid partition table

Disk /dev/sdc: 7743 MB, 7743995904 bytes
80 heads, 16 sectors/track, 11816 cylinders, total 15124992 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ea421

Device Boot      Start         End      Blocks   Id  System
/dev/sdc1   *        8064    15124991     7558464    b  W95 FAT32

Solution 1:

You don't mount the partition containing the LVM, you mount the partitions contained in the LVM. Try mounting /dev/mapper/vg1-lv1 instead of /dev/sdb8.

Additionally, since the drive is from a non-x86 NAS, you may need to mount it through fuseext2 due to the non-standard block size (read this question).