[dm-devel] dm snapshot does implicit resume?

Walter de Jong walter at sara.nl
Fri Apr 1 13:47:42 UTC 2005


Hi,

I'm not sure whether this is a dm or an lvm problem (or maybe it's a 
feature...) but it looks like snapshot does an implicit resume.
I have the feeling that this should be considered a bug.

observe:

dmsetup suspend /dev/mapper/some_vg-some_lv
lvcreate -s -L 10g -n snap /dev/some_vg/some_lv

The volume resumes automatigally without a need to run
dmsetup resume /dev/mapper/some_vg-some_lv



Also note how dmsetup requires the argument to be in the form
of "/dev/mapper/..." (/dev/some_vg/some_lv doesn't work here)
and lvcreate needs the form "/dev/some_vg/some_lv" 
(/dev/mapper/some_vg-some_lv doesn't work there) even though
they both have the same major,minor (in fact, /dev/some_vg/some_lv
is a symbolic link -> /dev/mapper/some_vg-some_lv)

This is on vanilla linux 2.6.11.6 (and many other 2.6.x versions)
with lvm2 2.01.04 and dmsetup 1.01.00

Greets,

      --Walter
-- 
                   *** If you build it, they will come ***

Walter de Jong
walter at sara.nl        http://www.sara.nl/
HPC Systems Programmer at SARA Computing and Network Services

People should be able to e-mail me, spambots should not.




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