My volume has disappeared

I created a 1TB volume yesterday using the CLIMB tutorial - I downloaded around 250GB to it, then set 2 jobs running (unicycler assemblies). This all seemed to work fine, but when I rebooted my machine (as message advising this when I logged in again) - the entire contents of the volume seems to have disappeared.

When I enter df -h, the volume (/dev/vdb) is not there anymore. However the directory /home/ubuntu/June1 is still there - this is where all my files were. The machine is a GVL: ubuntu@uobjune17, running at Birmingham.

Can my data be retrieved? Thanks,

Ed Bevan

Hi Ed,

The volume is still attached to this instance - you can check using the advanced interface.

Volumes can exist in three states when looking from inside an instance:

  1. Not attached
  2. Attached but not mounted
  3. Attached and mounted

df -h

will only display volumes that are in the third state - attached and mounted.

It might be that your volume is in the second state - attached but not mounted. You can use

lsblk

to list all of the attached volumes, whether they are mounted or not.

If your volume appears in the lsblk list without a mountpoint, all you need to do is run

sudo mount /dev/vdX [mountpoint]

where [mountpoint] is the directory where you want to mount your volume.

All data that was in the volume will still be in the volume, even if it has been completely detached from the instance. This means that you can detach and reattach volumes between instances to share data.

Volumes attached to instances are NOT automatically mounted on boot, so if you reboot your instance, prepare to have a moment’s shock when your files aren’t where you left them, then remember that you have to remount your volumes.

Thanks Matt that’s great!

1 Like

I have just rebooted an instance and lost my mount I reconnected with

sudo fdisk /dev/vdb
enter command w at prompt
sudo mkfs.ext4 /dev/vdb
sudo mount /dev/vdb vol/

the volume is now atached but it is empy, has the fdisk amd mkfs.ext4 destroyed the data. I guess I didnt need to do these stepps for a previously formated disk.

Could you let me know if it is likely that I can recover the data

thanks

Garry

Hi Garry - If you’ve formatted a disk with fdisk and made a new filesystem with mkfs there’s no way that the data that was previously on the disk is recoverable I’m afraid.

For future reference, always check for the disk with lsblk - it’ll show partitions already present (“vd” then a number to indicate the partition). Generally, if there’s a partition present, all you need to do is mount it with sudo mount <device> <mountpoint> to get to the data inside.