[dm-devel] Re: device mapper integrated loops - and one more year !
Bryn M. Reeves
breeves at redhat.com
Tue Nov 21 21:11:37 UTC 2006
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
devzero at web.de wrote:
> Hello !
>
> after desparately seeking for a solution to have more than 256 loop
> devices (for a huge cd-rom server), i have recently come across
> dm-loop, which looks very promising (to replace loop.c)
>
> can i have more than 256 devices which this?
Hi Roland,
Yes, dm-loop will support as many loop devices as device-mapper can allow.
> our cd-rom server is going to have more than 256 iso-images soon and
> i need to upgrade to a more recent OS, anyway, so this won`t be a
> problem that dm-loop is so brand new.
>
> but - any timeline for dm-loop mainline inclusion ?
>
> should i wait for 2.6.19 or 2.6.20 ?
There isn't a fixed timeline. We are currently working to improve the
lookup code - the prototype patch uses a linear search which doesn't
scale well for large/fragmented image files. I have some tests running
at the moment and we hope to have something soon - the results so far
are good, it's just a case of selecting between a couple of different
methods.
The changes dm-loop requires in device-mapper core are pretty minor and
have already been merged in 2.6.19, so it's just the dm-loop patch
itself remaining.
> is it already useable with less recent kernels, i.e. can i download
> dm-loop patch and recent dmsetup tool and use with older kernel ?
This should work fine - there are a couple of known issues with the
existing patch, but unless you are using large images (>2G), or have a
severely fragmented filesystem you shouldn't run into these.
I'll see if we can get a revised version of the current patch for wider
testing in the next couple of weeks - let me know if you would be
interested in trying this out.
Thanks,
Bryn.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2.2 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org
iD8DBQFFY2uJ6YSQoMYUY94RArTwAJwMmCJbTajxmX6Q/ps545zbgvJJOACg28NP
A+F6CtqcHH0fOG9lq2XQw/8=
=CzES
-----END PGP SIGNATURE-----
More information about the dm-devel
mailing list