quoted

I've recently set up a software RAID5 + bcache.

I'm using kernel 3.5.2 merged with bcache master branch. I'm quite
happy with the performance but
there is an important issue. I can't drop caches. Writing any number
to /proc/sys/vm/drop_caches
makes the system hung.

Furthermore, so far I've been unable to curb bcache's memory
consumption using the available
sysctl knobs.

Is this problem known?

No I didn't know about that - thanks, I'll look into it.

Thanks :)

Just out of curiousity, what are you doing? drop_caches isn't something
you want to use in normal operation...

Yeah, not normal operation, but this machine has 8 GB of ram and nearly 7
were being used by caches. I tried to launch a virtual machine and I couldn't.

Seeing the state the memory was in, I went off to drop the caches, and... hang.


-- 
Javier Marcet [off-list ref]