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Guacamole Multi-User Session Behavior

General Page

When multiple users access the same Guacamole connection, they may log in with separate Guacamole accounts, but they are all routed to one shared virtual machine (VM) using one shared OS-level username.
As a result, all users join the same active desktop session, causing overlapping actions and session interference.

Observed Behavior

Both users can open the Guacamole UI independently.

Once connected to the VM, all input/output is shared.

Actions performed by one user appear on the other user's screen.

Users are effectively competing for control of the same session.

This behavior is expected when a single VM is shared among multiple concurrent connections.

Root Cause

Guacamole does not create unique VM sessions when the connection uses one VM and one OS credential.
Instead, Guacamole attaches all users to the current active desktop session on that VM.

Resolution Options
Option 1 — Sequential Access (One User at a Time)

Allow only one user to connect to the VM at once.
This avoids session conflicts but does not support parallel work.

Option 2 — Provide Each User a Separate Reservation

Assign each user their own:

VM

Credentials

Independent Guacamole connection

This ensures full session isolation and prevents interference.

Recommended: Option 2 for any team working concurrently.

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Document Information

Modified date:
08 December 2025

UID

ibm17254137

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