gmirror using disk image files

[Ivan Voras]

Aragon Gouveia wrote:

> Is it possible to have Ggated export a Vnode device from one machine, and
> from the other machine import this device with Ggatec and mirror it with
> another Vnode device running locally with Gmirror?

You can do use mdconfig(8) to do anything geom-related with files, 
including mirroring them over the network. BUT, you can't mount the 
mirrored file system at the same time on both machines except if both 
mounts are read-only.

Combinations such as:

- mirrored devices/file systems mounted read-write on both machines
- mounted read-write on one machine and read-only on the other(s)

are all invalid and will sooner or later certainly result in system 
panic (not because of GEOM but because of the UFS). I'd tell you to try 
this: http://tdfs.sourceforge.net/ but it's really not production ready.