quoted

quoted

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.

Just tried it - I can reproduce it, but it's gone in 3.6. Looks like a
3.5 bug, not a bcache bug.

Oh, it was a coincidence then. I hadn't needed to use that for a long
time.

I'm gonna reset the master branch to my current dev branch soon as I've
tested it a bit more, but I'd suggest the bcache-3.2 branch - that's the
best tested code.

I cannot use a 3.2 kernel. This an HTPC too, besides a NAS and host for
vm guests. The tuners I have are supported from 3.4 onwards.

Do you mean there might be more problems with the master branch?

By the way. I have read in the manual how to add new cache devices, but
can you remove completely the caches in a 'clean way'? Imagine to change
it to a different disk which for some reason you cannot use at the same time.


-- 
Javier Marcet [off-list ref]