[linux-lvm] device-mapper & proc

[Joe Thornber]

On Fri, Oct 11, 2002 at 02:24:55AM -0700, Steven Stillaway wrote:
> LVM has /proc/lvm, DM does not seem to have anything
> equivalent.
> 
> Is there a reason for this?

Yes, device-mapper is a much lower level driver, it is not specific to
LVM (eg, it knows nothing about volume groups).  The information
simply isn't present in the kernel to be published in a /proc file.

> Is this likely to change?

No.

> I ask because my start scripts look for /proc/lvm --
> if I could have them check for /pro/lvm or /proc/dm
> and run the appropriate command that would be useful.

I'm not sure what you mean by 'appropriate command', what information
are you getting from /proc/lvm that you can't get from the userland
tools ?  If you just want to see if device-mapper is present:

grep device-mapper /proc/devices

- Joe