The Book of Xen

Xen's Logs

These error messages make a good start for Xen troubleshooting, but sometimes they're not helpful enough to solve the problem. In these cases, we need to dig deeper.

dmesg and xm dmesg

Although the output of xm dmesg isn't a log in the usual sense of a log file, it's an important source of diagnostic output. If you've got a problem whose source isn't obvious from the error message, begin by looking at the Xen kernel message buffer. As you probably know, the Linux dmesg command prints out the Linux kernel's message buffer, which ordinarily contains all kernel messages since the system's last boot (or, if the system's been up for a while, it displays a succession of boring status messages).

Because Xen could be said to act as a kernel in ...