debian VPS - auth.log flooded with “No such file or directory”

Question

i was browsing through the questions here in serverfault and I decided to take a look in my /var/log/auth.log . And I discovered that 2 lines are being added repeatedly

Mar  8 10:17:19 slides getty[14194]: /dev/xvc0: No such file or directory
Mar  8 10:17:19 slides getty[14195]: /dev/hvc0: No such file or directory

There are no obvious intervals. There may be 6 in 10 seconds, there may be 2 in 5 minutes. So what may be causing this?

The VPS is running Debian Squeeze, fully updated and otherwise works fine.

PS: It's a XEN VPS if it matters.

Answer 1

hvc0 used to be used by the xen kernels to provide a serial terminal from the host machine. So if your VPS pre-dates this move, or the image they used still points to them; well, it'll be noisy. You'll probably see messages about getty respawning too fast in dmesg too (they should explain the odd gaps, as it'll stop getty respawning for a while if it's doing exactly this).

Try:

$ cat /proc/cmdline 
root=LABEL=root ro console=hvc0

If you have an entry (as I do) for console=hvc0, or xvc0, then the corresponding devices should exist in /dev. If this is the case, let us know and we can find out what their node numbers are to create them, or contact your VPS host's support.

If you have console=tty1, which I believe it's default/expected now, you can remove the xvc0/hvc0 entries from /etc/inittab (or if using Upstart, I believe they're separate files under /etc/init/).

If you're unsure about anything, it'd probably be wise to hit up the VPS' support. This is how your VM communicates with the host, so it's useful to have functioning cleanly.