[SOLVED] Full disk on VM but can't find files taking up space

[frazzyfin]

Hi, I'm a beginner when it comes to Proxmox and VM's so please bear with me.

I have a VM in Proxmox running Ubuntu. The storage for it is on an lvmthin pool. On the image below it is vm-100-disk-1.



In my VM the disk is apparently full. df -h shows 100% usage as seen below.



However, when searching for the files which are taking up all the space using sudo ncdu, it shows that there is only 34GB of total disk usage, which contradicts the 80GB that df shows above:


So there is around 50GB of files that are 'missing', and I can't free up the space without finding what's wrong. I have a feeling that it's something with the Proxmox storage setup for the VM but I don't know what. Can anyone help?

I have also run lsof to see if there's any files waiting to be deleted but it doesn't show anything abnormal.

Thanks.

 

[wolfgang]

Hi,

"du" shows the real used data but this is not the same as the allocated data that are shown by df.
An example you have default 4k blocks and white just 1K of this block then you have 1K real data but 4K allocated.

 

[dcsapak]

also try 'ncdu -x' to not cross over filesystem boundaries, maybe you overmounted a directory

 

[BobhWasatch]

Could also be out of inodes if you have lots of small files. Check "df -i" for that.

 

[frazzyfin]

I've figured out my problem. I had mounted a CIF share to /mnt/my_cif_share/ but before mounting this folder already had 50GB of files in it. As far as I can tell mounting over it essentially 'hides' those files from du and similar tools.

To rectify, you can either unmount the share, and delete the 'hidden' files. Or to fix this without unmounting, you can remount your root folder using mount -o bind / /mnt and you will be able to delete the files from there.