Re: dynamically created /dev/null is a regular file

[Brook Milligan <brook%nmsu.edu@localhost>]

On Jun 26, 2015, at 1:07 AM, Martin Husemann wrote:
> I don't get it - we are talking about the case where init finds no 
> /dev/console, so it mounts a tmpfs on /dev and then (on the empty tmpfs)
> runs MAKEDEV ?
> 
> Where does /dev/null get created if not inside MAKEDEV then? Or is
> the tmpfs mount failing?

After poking around a bit, it seems that the extra /dev/null is left over in the DOMU filesystem from shutting it down.  Here is some more information:

- The system in question is an amd64 DOMU.

- The /dev filesystem is initially empty; just MAKEDEV*, a couple of directories and log.

- Upon first boot of the DOMU all is fine; tmpfs is mounted, /dev/null is fine, etc.

- After shutting down the DOMU, there is a leftover /dev/null (regular file) in the DOMU filesystem; the rest of /dev is the same as it was initially (i.e., mostly empty).

Does this mean that something is writing to the DOMU /dev/null after the tmpfs is unmounted?  What could that be?

Thanks again for your help.

Cheers,
Brook