On Tue, Apr 09 2013 at 3:35pm -0400, Kent Overstreet <koverstreet@xxxxxxxxxx> wrote: > On Tue, Apr 09, 2013 at 10:07:36AM -0400, Mike Snitzer wrote: > > Hey Kent, > > > > No matter what I specify via make-bcache's -b and -w args they are > > always 512k and 512b respectively, e.g.: > > > > # make-bcache -B /dev/mapper/test-dev-174467 -C /dev/mapper/test-dev-24832 --cache_replacement_policy=fifo -b 2048k --writeback --discard > > UUID: 3705b1d8-4b44-406c-abf2-594c0cb146be > > Set UUID: a16dc554-c054-4a24-90fa-40f624e3a652 > > nbuckets: 8192 > > block_size: 1 > > bucket_size: 1024 > > nr_in_set: 1 > > nr_this_dev: 0 > > first_bucket: 1 > > UUID: 46a37bba-2582-4533-a95b-1eb29c71e53f > > Set UUID: a16dc554-c054-4a24-90fa-40f624e3a652 > > nbuckets: 512 > > block_size: 1 > > bucket_size: 1024 > > nr_in_set: 1 > > nr_this_dev: 0 > > first_bucket: 1 > > > > # cat /sys/block/bcache3/bcache/cache/bucket_size > > 512k > > > > I can take a look at the make-bcache source in a bit but figured I'd let > > you know sooner rather than later. > > Oh, it's because you specified the bucket size after the device. If you > specify the devices last it'll work. > > So it's definitely unintuitive and semi broken, the reason it works that > way is for formatting backing devices and cache devices at the same > time; it walks through the options, and when it sees a device it formats > it with the options seen so far. OK, thanks for the insight. > Right way to do it would be to make two passes... Or just defer the formatting until all args are processed. > I suppose I should just do that so it doesn't trip other people up. Yeah, probably for the best. Thanks. -- 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
