[dm-devel] [RFC] File backed target for device-mapper
Alasdair G Kergon
agk at uk.sistina.com
Tue Jul 22 16:59:01 UTC 2003
On Tue, Jul 22, 2003 at 11:17:39PM +0200, Christophe Saout wrote:
> I just wrote a dm target uses a file as backend instead of another block
> device.
Another suggestion:
A target that always returns a block of zeros [or more generally,
some other repeating pattern e.g. if the read goes beyond the end
of your file - required to be multiple of sector size - it loops
round to the beginning; writes get dropped]
So you can easily create, for example a /dev/zero-like block device of
arbitrary size, which might be useful for replacing a lost disk that
contained a stripe if you want to read off the data from the other
stripes at correct offsets.
Alasdair
--
agk at uk.sistina.com
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