On Thu, 15 February 2007 19:38:14 +0100, Juan Piernas Canovas wrote:Actually, the version of DualFS for Linux 2.4.19 implements a cleaner. In our case, the cleaner is not really a problem because there is not too much to clean (the meta-data device only contains meta-data blocks which are 5-6% of the file system blocks; you do not have to move data blocks).
The patch for 2.6.11 is not still stable enough to be released. Be patient
;-)
While I don't want to discourage you, this is about the point in
development where most log structured filesystems stopped. Doing a
little web research, you will notice those todo-lists with "cleaner"
being the top item for...years!
Getting that one to work robustly is _very_ hard work and just today
I've noticed that mine was not as robust as I would have liked to think.
Also, you may note that by updating to newer kernels, the VM writeout
policies can change and impact your cleaner. To an extent even that you
had a rock-solid filesystem with 2.6.18 and thing crumble between your
fingers in 2.6.19 or later.
If the latter happens, most likely the VM is not to blame, it just
proved that your cleaner is still getting some corner-cases wrong and
needs more work. There goes another week of debugging. :(
Jörn