vmlab tail

vmlab tail follows a file inside a guest over the vmlab agent channel, with tail -F semantics: it keeps reading as the file grows and follows it across truncation and replacement. No guest network and no guest shell are needed.

vmlab tail <VM> <PATH>

The command asks the lab daemon to open a tail session on the machine's agent and prints each chunk as it arrives, flushing after every chunk so a pipe sees lines promptly. It runs until you press Ctrl-C, the machine stops, or the agent reports an error on the session. The daemon checks the machine's state every half second and ends the stream when it is no longer running.

The path is read by the agent's own identity, SYSTEM or root, so files a user cannot read are still followed. This is the verb for a guest log that has no host-side copy; the lab's own event log and a VM's serial and QEMU logs are read host-side by vmlab logs.

vmlab tail dc01 C:/Windows/debug/netsetup.log
vmlab tail nix01 /var/log/messages

Exit status is 0 when the stream ends. not_found (4) means the lab declares no machine by that name. failed (1) covers a machine that is not running, an agent that does not answer, and a session error such as a path the agent cannot open.