On Tue, Aug 21, 2012 at 02:31:18AM +0200, Javier Marcet wrote: > >> >> 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. Yeah. Weird bug. > > 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? Perhaps, but mainly it tracks mainline pretty closely. > 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. Yep. echo 1 > /sys/fs/bcache/<cache set>/unregister -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
