> 2. I have setup an LVM above bcache, and /dev/sda4 is the only cache > partition. The whole thing was setup with: > > make-bcache -B /dev/sda4 -C /dev/sdb > > the LVM is "inside" /dev/sda4 > 3. I am using fio as a benchmark, have setup writeback > # cat /sys/block/bcache0/bcache/writeback_running > 1 > and I think I have followed every hints I could found about performance tuning. > Yet, when running the ssd fio test suite on a file on partition that > is not "cached", I am obtaining the following figures: > seq-read: iops=29156 > rand-read: iops=291 > seq-write: iops=22355 > rand-write: iops=260 > > Running it on a cached file system I'm obtaining: > seq-read: iops=22196 > rand-read: iops=330 > seq-write: iops=15864 > rand-write: iops=387 > > What am I missing ? Outside of the make-bcache, none of the commands you give in the thread prove that the cache is assembled (it's actually possible to have writeback_running = 1 with a detached bdev, though that's a bug in my opinion). What does `ls -d /sys/fs/bcache/*/bdev*` show? -- 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