Hard drive not mounting

lithrandir · 09-04-2016, 08:47 AM

Hi,

We have a Linux system on our computer, which had a hard drive (sdb1) placed by a colleague. We need to retrieve the files in that hard drive, but unfortunately the Linux system doesn't seem to mount it properly (?) It doesn't seem to recognize its file system.

Code:

-bash-4.1$ lsblk
NAME                          MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sdb                             8:16   0 278.5G  0 disk 
└─sdb1                          8:17   0 278.5G  0 part 
sda                             8:0    0 278.5G  0 disk 
├─sda1                          8:1    0   200M  0 part /boot/efi
├─sda2                          8:2    0   500M  0 part /boot
└─sda3                          8:3    0 277.8G  0 part 
  ├─vg_nj1-lv_root (dm-0) 253:0    0    50G  0 lvm  /
  ├─vg_nj1-lv_swap (dm-1) 253:1    0   3.8G  0 lvm  [SWAP]
  └─vg_nj1-lv_home (dm-2) 253:2    0   224G  0 lvm  /home
sr0                            11:0    1  1024M  0 rom  

fdisk -l

Disk /dev/sdb: 299.0 GB, 298999349248 bytes
255 heads, 63 sectors/track, 36351 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003e75a

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1       36351   291989376   8e  Linux LVM

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


Disk /dev/sda: 299.0 GB, 298999349248 bytes
255 heads, 63 sectors/track, 36351 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1       36352   291991551+  ee  GPT

Disk /dev/mapper/vg_nj1-lv_root: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_nj1-lv_swap: 4110 MB, 4110417920 bytes
255 heads, 63 sectors/track, 499 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_nj1-lv_home: 240.5 GB, 240463642624 bytes
255 heads, 63 sectors/track, 29234 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Thanks.

unSpawn · 09-04-2016, 09:24 AM

You haven't shown any errors to support the OS doesn't mount the LVMs properly on boot. So boot the machine, become root, then check 'dmesg' output and system logs for clues then try 'vgscan; vgchange -ay; dmsetup status;'?

lithrandir · 09-04-2016, 10:32 PM

Quote:

Originally Posted by unSpawn

You haven't shown any errors to support the OS doesn't mount the LVMs properly on boot. So boot the machine, become root, then check 'dmesg' output and system logs for clues then try 'vgscan; vgchange -ay; dmsetup status;'?

I've done su, the lsblk shows the same for sdb. How do I mount sdb and check its content? Sorry, I'm new to this. Below are the outputs from several commands:

[root@nj1 CgWi]# lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 278.5G 0 disk
└─sdb1 8:17 0 278.5G 0 part
sda 8:0 0 278.5G 0 disk
├─sda1 8:1 0 200M 0 part /boot/efi
├─sda2 8:2 0 500M 0 part /boot
└─sda3 8:3 0 277.8G 0 part
├─vg_njuhep1-lv_root (dm-0) 253:0 0 50G 0 lvm /
├─vg_njuhep1-lv_swap (dm-1) 253:1 0 3.8G 0 lvm [SWAP]
└─vg_njuhep1-lv_home (dm-2) 253:2 0 224G 0 lvm /home
sr0 11:0 1 1024M 0 rom

[root@nj1 CgWi]# dmesg | grep sdb
sd 0:2:1:0: [sdb] 583983104 512-byte logical blocks: (298 GB/278 GiB)
sd 0:2:1:0: [sdb] Write Protect is off
sd 0:2:1:0: [sdb] Mode Sense: 1f 00 10 08
sd 0:2:1:0: [sdb] Write cache: disabled, read cache: enabled, supports DPO and FUA
sdb:
sda: sdb1
sd 0:2:1:0: [sdb] Attached SCSI disk

[root@nj1 CgWi]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "vg_nj1" using metadata type lvm2

[root@nj1 CgWi]# vgchange -ay
3 logical volume(s) in volume group "vg_nj1" now active

[root@nj1 CgWi]# dmsetup status
vg_nj1-lv_home: 0 469655552 linear
vg_nj1-lv_swap: 0 8028160 linear
vg_nj1-lv_root: 0 104857600 linear

syg00 · 09-04-2016, 11:28 PM

I wonder if sdb has a vg of the same name - check dmesg (unfiltered) after the vgchange.

unSpawn · 09-05-2016, 01:34 AM

Quote:

Originally Posted by lithrandir

(..)

Code:

  ├─vg_njuhep1-lv_root (dm-0) 253:0    0    50G  0 lvm  /
  ├─vg_njuhep1-lv_swap (dm-1) 253:1    0   3.8G  0 lvm  [SWAP]
  └─vg_njuhep1-lv_home (dm-2) 253:2    0   224G  0 lvm  /home

(..)

[root@nj1 CgWi]# dmsetup status
vg_nj1-lv_home: 0 469655552 linear 
vg_nj1-lv_swap: 0 8028160 linear 
vg_nj1-lv_root: 0 104857600 linear

...shows the devices active and ready, now you mount them. *If not done already so: check output of the "mount;" command first! For example "/proc/dm-2" equals "/dev/mapper/vg_nj1-lv_home" so you can mount either manually ("mount /dev/mapper/vg_nj1-lv_home -t auto /home;") or put the stanzas in /etc/fstab. **The latter goes esp. for "/" (dm-0) as you can't do that once you've entered the OS.