mjhjmtu

I installed a LVM storage on my computer and I had very important information inside /HFT.

Here is the way I installed that LVM storage:

1. sudo pvcreate /dev/sdb1 /dev/sdc1


2. sudo vgcreate VG /dev/sdb1 /dev/sdc1


3. sudo lvcreate -n LV -L 3T VG


4. 
   sudo mkfs .ext3 /dev/VG/LG (could be .ext4)


5. mkdir /HFT


6. sudo mount /dev/VG/LG /HFT

Before restarting, I got a nice 3TB storage, I could see it clearly with df -h. Now, after restarting my computer, if I make df -h, I got

┌─╼ [~]
└╼ cd /dev
autofs disk fuse i2c-11 input loop-control psaux sdb sg5 tty0 tty20 tty32 tty44 tty56 ttyS0 ttyS20 ttyS4 vboxdrvu vcsa3
block dm-0 fw0 i2c-12 kmsg mapper ptmx sdb1 sg6 tty1 tty21 tty33 tty45 tty57 ttyS1 ttyS21 ttyS5 vboxnetctl vcsa4
bsg dm-1 hidraw0 i2c-13 kvm mcelog ptp0 sdc sg7 tty10 tty22 tty34 tty46 tty58 ttyS10 ttyS22 ttyS6 vboxusb vcsa5
btrfs-control dm-2 hidraw1 i2c-14 lightnvm mei0 ptp1 sdd sg8 tty11 tty23 tty35 tty47 tty59 ttyS11 ttyS23 ttyS7 vcs vcsa6
bus dm-3 hidraw2 i2c-2 log mem pts sde shm tty12 tty24 tty36 tty48 tty6 ttyS12 ttyS24 ttyS8 vcs1 vfio
cdrom dri hidraw3 i2c-3 loop0 memory_bandwidth random sdf snapshot tty13 tty25 tty37 tty49 tty60 ttyS13 ttyS25 ttyS9 vcs2 vga_arbiter
cdrw drm_dp_aux0 hidraw4 i2c-4 loop1 mqueue rfkill sdg snd tty14 tty26 tty38 tty5 tty61 ttyS14 ttyS26 ubuntu-vg vcs3 vhci
char dvd hpet i2c-5 loop2 net rtc sdh sr0 tty15 tty27 tty39 tty50 tty62 ttyS15 ttyS27 uhid vcs4 vhost-net
console dvdrw hugepages i2c-6 loop3 network_latency rtc0 sg0 stderr tty16 tty28 tty4 tty51 tty63 ttyS16 ttyS28 uinput vcs5 vhost-vsock
core ecryptfs hwrng i2c-7 loop4 network_throughput sda sg1 stdin tty17 tty29 tty40 tty52 tty7 ttyS17 ttyS29 urandom vcs6 zero
cpu fb0 i2c-0 i2c-8 loop5 null sda1 sg2 stdout tty18 tty3 tty41 tty53 tty8 ttyS18 ttyS3 usb vcsa
cpu_dma_latency fd i2c-1 i2c-9 loop6 port sda2 sg3 tpm0 tty19 tty30 tty42 tty54 tty9 ttyS19 ttyS30 userio vcsa1
cuse full i2c-10 initctl loop7 ppp sda3 sg4 tty tty2 tty31 tty43 tty55 ttyprintk ttyS2 ttyS31 vboxdrv vcsa2
┌─╼ [/dev]
└────╼ df -h
Filesystem Size Used Avail Use% Mounted on
udev 34G 0 34G 0% /dev
tmpfs 6.7G 11M 6.7G 1% /run
/dev/mapper/ubuntu--vg-root 151G 61G 83G 43% /
tmpfs 34G 29M 34G 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 34G 0 34G 0% /sys/fs/cgroup
/dev/sda2 705M 401M 253M 62% /boot
/dev/sda1 511M 4.7M 507M 1% /boot/efi
tmpfs 6.7G 16K 6.7G 1% /run/user/121
tmpfs 6.7G 20K 6.7G 1% /run/user/1000
/home/infinity/.Private 151G 61G 83G 43% /home/infinity

Now, /HFT still exists, but it is empty.

I don't know if I lost everything. Is there a way to restore information? Why is the whole procedure cleared up everything once I rebooted my computer? What is the proper way that such an error does not happen again in the future?

UPDATE

sudo lvdisplay
 WARNING: Device for PV rat7TF-lEMd-U3Gi-29du-7Fn3-2bNC-9CVmqL not found or rejected by a filter.
 --- Logical volume ---
 LV Path /dev/VG/LV
 LV Name LV
 VG Name VG
 LV UUID Bm0ThM-KWDU-oyjm-F8Zt-NXdF-yyFO-2rvM9d
 LV Write Access read/write
 LV Creation host, time infinity-ThinkStation-D30, 2018-04-16 15:00:57 -0400
 LV Status NOT available
 LV Size 3.00 TiB
 Current LE 786432
 Segments 2
 Allocation inherit
 Read ahead sectors auto

 --- Logical volume ---
 LV Path /dev/ubuntu-vg/root
 LV Name root
 VG Name ubuntu-vg
 LV UUID f1TYvS-XFq1-Z6Nu-iuXg-H95j-0XUN-8J4vi3
 LV Write Access read/write
 LV Creation host, time ubuntu, 2017-11-14 13:28:06 -0500
 LV Status available
 # open 1
 LV Size 154.38 GiB
 Current LE 39522
 Segments 1
 Allocation inherit
 Read ahead sectors auto
 - currently set to 256
 Block device 253:1

 --- Logical volume ---
 LV Path /dev/ubuntu-vg/swap_1
 LV Name swap_1
 VG Name ubuntu-vg
 LV UUID q2kHAa-Q3jc-8C1t-JQvi-PtTo-3KR4-zoNH2a
 LV Write Access read/write
 LV Creation host, time ubuntu, 2017-11-14 13:28:07 -0500
 LV Status available
 # open 1
 LV Size 67.92 GiB
 Current LE 17387
 Segments 1
 Allocation inherit
 Read ahead sectors auto
 - currently set to 256
 Block device 253:2

UPDATE 2

┌─╼ [/]
└────╼ fdisk -l /dev/sdc
fdisk: cannot open /dev/sdc: Permission denied
┌─╼ [/]
└╼ sudo fdisk -l /dev/sdc
Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 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
Disklabel type: dos
Disk identifier: 0x9619624a

Device Boot Start End Sectors Size Id Type
/dev/sdc1 2048 3907026943 3907024896 1.8T 7 HPFS/NTFS/exFAT

I tried to run sudo mount /dev/VG/LV /HFT, but it seems not working fine. I've had the problem mount: /HFT: special device /dev/VG/LV does not exist.

UPDATE 3

root@infinity-ThinkStation-D30:/HFT# lvchange -ay --activationmode partial /dev/VG/LV
 PARTIAL MODE. Incomplete logical volumes will be processed.
 WARNING: Device for PV rat7TF-lEMd-U3Gi-29du-7Fn3-2bNC-9CVmqL not found or rejected by a filter.

┌─╼ [/HFT]
└╼ sudo mount /dev/VG/LV /HFT
mount: /HFT: can't read superblock on /dev/mapper/VG-LV.

What's happened here is that you don't have /dev/sdc1, which contains half of the volume group VG. Without it you cannot activate VG, which in turn means you cannot access the logical volume LV.

Currently you no access to any of your data on VG/LV. It might be stored on the missing disk, or you might be lucky and enough of it might be on the disk that's present.

Non-invasive steps I would recommend you take:

1. Power off your system. Carefully check all the connectors for disk /dev/sdc to ensure it is fully connected. Restart.


2. Run fdisk -l /dev/sdc to see if the partition even exists.


3. Look in /etc/lvm/lvm.conf to see if there's a filter blocking access to your /dev/sdc1. Ignore all lines beginning with #. None of the rest should have a keyword that mentions filter.

Invasive steps I would not recommend you take unless everything else has failed:

1. 
   

   Run vgchange -ay /dev/VG --activationmode partial

   
   
   

   THIS ↑ ↑ MAY DESTROY YOUR DATA. On the other hand it may let you recover it.

   
   



2. Run mount -o ro,noload /dev/VG/LV /HFT to mount what filesystem it can find and see if any of the data is present. If it is, copy it to a safe place and rebuild your LVM volume group. The mount is read-only so you won't be able to change anything in the LV.

As an aside, if you have important data there are two things you can do to mitigate its potential loss

1. Take regular automated backups. Preferably to a separate location. (I use a cloud storage provider.)


2. Use RAID 1 to mirror data across two same-sized disks. You'll need 2x 3TB disks to store 3TB data but it's worth it. Really it is. You can do this either using the mdadm RAID toolset or directly in LVM.