kasm installation keeps failing

[fyonnuk]

Hello everyone. I'm trying to install kasm from the proxmox community scripts and the install keeps failing.

just using the default settings I get this:

  ⚙️  Using Default Settings on node pve
  💡  PVE Version 9.2.11 (Kernel: 7.0.14-15-pve)
  🆔  Container ID: 107
  🖥️  Operating System: debian (13)
  📦  Container Type: Privileged
  💾  Disk Size: 30 GB
  🧠  CPU Cores: 2
  🛠️  RAM Size: 8192 MiB
  🚀  Creating a Kasm LXC using the above default settings
  
  ✔️  Storage local (Free: 276.7GB  Used: 17.7GB) [Template]
  ✔️  Storage local-zfs (Free: 276.7GB  Used: 135.8GB) [Container]
  ✔️  Storage 'local-zfs' (zfspool) validated
  ✔️  Template storage 'local' validated
  ✔️  Cluster is quorate
  ✔️  Template search completed
  ✔️  Template debian-13-standard_13.1-2_amd64.tar.zst [local]
  ✔️  LXC Container 107 was successfully created.
  ✔️  USB passthrough configured
  ✔️  Started LXC Container
  ✔️  Network in LXC is reachable (ping)
  ✔️  Customized LXC Container
  ✔️  Set up Container OS
  ✔️  Network Connected: 192.168.1.109
  ✔️  IPv4 Internet Connected
  ✔️  IPv6 Internet Connected
  ✔️  Git DNS: github.com:(✔️ ) raw.githubusercontent.com:(✔️ ) api.github.com:(✔️ )
  ✔️  Updated Container OS
  ✔️  Installed Docker
  ✔️  Detected Kasm Workspaces version 1.19.0
  💡   WARNING: This script will run an external installer from a third-party source (https://www.kasmweb.com/).
  💡   The following code is NOT maintained or audited by our repository.
  💡   If you have any doubts or concerns, please review the installer code before proceeding:
          🌐    →  install.sh inside tar.gz https://kasm-static-content.s3.amazonaws.com/kasm_release_1.19.0-latest.tar.gz

      Do you want to continue? [y/N]: y
  ✖️  in line 75: exit code 255 (DPKG: Fatal internal error): while executing command bash /opt/kasm_release/install.sh --ignore-dep-failures > ~/kasm-install.output 2>&1

  --- Last 20 lines of log ---


To run the Docker daemon as a fully privileged service, but granting non-root
users access, refer to https://docs.docker.com/go/daemon-access/

WARNING: Access to the remote API on a privileged Docker daemon is equivalent
         to root access on the host. Refer to the 'Docker daemon attack surface'
         documentation for details: https://docs.docker.com/go/attack-surface/

================================================================================


[2026-09-07 11:17:52] [OK] Installed Docker
[2026-09-07 11:17:52] [INFO] Detecting latest Kasm Workspaces release
[2026-09-07 11:17:53] [OK] Detected Kasm Workspaces version 1.19.0
[2026-09-07 11:17:53] [WARN] WARNING: This script will run an external installer from a third-party source (https://www.kasmweb.com/).
[2026-09-07 11:17:53] [WARN] The following code is NOT maintained or audited by our repository.
[2026-09-07 11:17:53] [WARN] If you have any doubts or concerns, please review the installer code before proceeding:
[2026-09-07 11:17:53] →  install.sh inside tar.gz https://kasm-static-content.s3.amazonaws.com/kasm_release_1.19.0-latest.tar.gz
[2026-09-07 11:17:56] [INFO] Installing Kasm Workspaces
[2026-09-07 11:18:36] [ERROR] in line 75: exit code 255 (DPKG: Fatal internal error): while executing command bash /opt/kasm_release/install.sh --ignore-dep-failures > ~/kasm-install.output 2>&1
  -----------------------------------

  ✖️  Installation failed in container 107 (exit code: 255)
  📋  Installation log: /tmp/kasm-107-75d1f32b.log

  Error: DPKG: Fatal internal error

What would you like to do?

  1) Remove container and exit
  2) Keep container for debugging
  3) Retry with verbose mode (full rebuild)
  4) Repair APT/DPKG state and re-run install (in-place)

Select option [1-4] (default: 1, auto-remove in 60s): 2

  Container 107 kept for debugging
root@pve:~#

that log file is mostly a repeat of what I've put above. the error on line 75 is interesting as line 76 is:

IGNORE_DEP_FAILURES=${IGNORE_DEP_FAILURES:-false}

Any ideas? many thanks

[MickLesk]

@CrazyWolf13 kasm again ^^

[fyonnuk]

I did search for kasm before I posted this, and found just one other post and they seemed to have a different error.

[MickLesk]

Kasm Break every few months

[fyonnuk]

oh.. is that just the proxmox community scripts, or is that true of any installation? maybe I should find a different home VDI instance? any recommendations?

[CrazyWolf13]

@MickLesk @fyonnuk Weird, I just tested the kasm script successfully and it built without issues at all.

Can you try again? and if it still fails check from the lxc if you can reach the asset at: https://kasm-static-content.s3.amazonaws.com/kasm_release_1.19.0-latest.tar.gz

What system is this? an amd64 or arm?

EDIT: I just see now, reaching the script should not be an issue, as one can see in the log.

[fyonnuk]

I'm running amd64 (no fancy modern arm servers here, just an old HP mini :) )

okay, I ran the installer with the var_verbose=1 bash xxx like you suggested and it still failed. here is the full install log.. really not sure it's told me anything I didn't already show you though...

kasm_install.log

feel like I must be doing something stupid, but I'm not sure what...

[MickLesk]

Can you hold the broken Container, then pct enter inside the container and cat or tail the Log? Example:

pct exec 116 -- bash -lc 'tail -n 150 /root/kasm-install.output'

Or

pct enter 116
cat /root/kasm-install.output

[fyonnuk]

meh, I'll just scp the file to this laptop and upload the whole file :)

kasm-install.output.txt

at the end it looks like it's complaining about swap...?

[MickLesk]

Our Docs on Website: "Kasm needs swap (on Proxmox host) and activated FUSE to be installed successfully!"

[fyonnuk]

oh.. I have no swap on this box... why would I have no swap...? whenever I installed it, I would have assumed the setup would just set up swap, I can't imagine I would have disabled it... I am confused... well, if that's the answer then that's the answer... supposed I should set up a swapfile now...

[MickLesk]

You need working Swap ON your Host, then it worked for LXC too

[fyonnuk]

hmm.. a little googling indicates that proxmox standard setup on zfs defaults to no swap.. never even noticed that...

[fyonnuk]

well, I installed zram and that was enough for kasm to move ahead and install. thanks for your help everyone!

I wonder if it's worth a mention on the kasm page that it's not just that this needs swap but that a default install may mean that they have no swap?