Rescue mount: /dev/nbd0: can't read superblock


#1

Created a CS2 Bare Metal with Debian Jessie (nbd0, 50GB, LSSD), booted in rescue mode, trying to mount nbd0 root@xx:~# mkdir -p /mnt/volume0
root@xx:~# mount /dev/nbd0 /mnt/volume0
mount: /dev/nbd0: can’t read superblock
Any advices?


#2

This community is very disappointing. There are only two reasons for no reactions: Ignorance or egoism. This is out of place in this day and age.


#3

your ignorance seems to exceed your intelligence.

Why should people answer, if they have no clue? Do you really want to have a thread filled hundreds if answer of “no idea, sorry bud” ? Ever thought about that?

I have no clue either, but in the most cases (yeah i googled, you could have done the same…) it is related to a faulty usb port with not enough power to power the device (i.e. external usb hdd). since this is no USB device, you probably either have a corrupted image or a corrupted ssd.

To check this, create a snapshot, and create a new server with the new snapshot.
If the error persists, you have a faulty filesystem and you might want to look for recovery solutions.


#4

Dear gentlemon,

thank you for your response and yes, you are right. I was too fast with my statement. Sorry for that to everybody. I would not have thought that this is such a big problem.


#5

Hi Xela,

I can’t mount any nbdx in rescue mode neither.

A possible workaround is to attach and mount the volume in another instance.


#6

Just a heads-up. With the current rescue image this happens because nbd0 isn’t connected to anything - there is no nbd-client running.

Here’s what you need to do:

  1. Install the NBD client, since it’s missing for some reason: apt-get update && apt-get install nbd-client
  2. Look for your volume’s address in the dashboard. Find your server and look at the very bottom of the page, where the volumes are listed. Let’s say it’s nbd://10.1.2.3:1234
  3. Start NBD client with the IP and port number from the previous step: nbd-client 10.1.2.3 1234 /dev/nbd0 (obviously, the IP and port number will be different for your server)
  4. And now nbd0 is connected so you can mount the volume with mount /dev/nbd0 /mnt/volume0. If that fails then you’ve either copied something wrong, your server has network or storage problems, or your filesystem is corrupt. Be sure to take a snapshot before trying to recover.

#7

Hey @drdaeman !

I tried your solution but it doesn’t seem to work anymore with the new rescue images.

Can you help ?

Thanks a lot !


#8

Just answering this 2 years later maybe it will help someone.

run ‘lsblk’ to list the partitions then mount the specific partition.

root# lsblk
nbd0 43:0 0 46.6G 0 disk
├─nbd0p15 43:15 0 100M 0 part
└─nbd0p1 43:1 0 46.5G 0 part

then

root# mkdir -p /mnt/volume0
root# mount /dev/nbd0p1 /mnt/volume0

#scaleway has a bad customer service culture… love this company, but this company is going no where with this level of customer support.