I did a reboot and got it registered again. bio: create slab <bio-1> at 1 bcache: invalidating existing data bcache: registered cache device sdb bcache: Caching sdc, inserted new UUID 87ba7904-7690-4985-b6a8-daeba41712a3 EXT4-fs (bcache0): mounted filesystem with ordered data mode. Opts: (null) First read went at 119 MB/Sec, second at 37MB/Sec Here's what's in stats_hour /sys/block/sdc/bcache/stats_hour/cache_bypass_hits :::::::::::::: 44 :::::::::::::: /sys/block/sdc/bcache/stats_hour/cache_bypass_misses :::::::::::::: 81172 :::::::::::::: /sys/block/sdc/bcache/stats_hour/cache_hit_ratio :::::::::::::: 0 :::::::::::::: /sys/block/sdc/bcache/stats_hour/cache_hits :::::::::::::: 24 :::::::::::::: /sys/block/sdc/bcache/stats_hour/cache_miss_collisions :::::::::::::: 14 :::::::::::::: /sys/block/sdc/bcache/stats_hour/cache_misses :::::::::::::: 407422 :::::::::::::: /sys/block/sdc/bcache/stats_hour/cache_readaheads :::::::::::::: 0 With echo 0 >/sys/block/sdc/bcache/sequential_cutoff 33 MB/Sec On Tue, 2012-02-14 at 22:24 -0800, Kent Overstreet wrote: > Not sure what's going on with not being able to register again - not a > lot of info to go off of. It was working last I checked in the > bcache-3.2-dev branch, it might be buggy in the older bcache branch. > > >From your numbers it looks like the 8 gb of data wasn't in the cache - > bcache bypasses sequential IO by default. You can flip it off by > echoing 0 to sequential_cutoff. > > On Tue, Feb 14, 2012 at 9:26 PM, Franco <franco@xxxxxxxxxxxxxxxx> wrote: > > Hi > > > > I was in the process of testing linux-bcache but was seeing some strange > > behaviour so I thought I would remount my cached filesystem. I then > > noticed that the performance results started looking like the cache just > > wasn't there, so I unregistered it: > > > > bcache: Cache set be008612-38aa-4082-9f42-1bada25cb002 unregistered > > bcache: Caching disabled for sdc > > > > but now when I try to register it again, I get bcache: error > > opening /dev/sdb: device busy. > > > > I haven't tried rebooting yet but probably will do after I've sent this > > message. > > > > These were the strange results I was getting that prompted me to unmount > > and remount the filesystems. > > > > Setup: hardware RAID 5 16 disk array with 2 partitions, 1 Intel 40GB SSD > > for bcache. > > > > Filesystem Size Used Avail Use% Mounted on > > /dev/bcache0 1.9T 26G 1.8T 2% /data33 > > /dev/sdd 1.9T 23G 1.8T 2% /data34 > > > > Wrote an 8GB file to each filesystem, then tried reading it back. > > Machine has 8GB RAM. > > > > Speed for random reads from identical SSD = 181.766523 MB/Sec, random > > read test done in the following order with measured speed in MB/Sec. The > > random IO is actually just reading with a 4GB stride, wrapping around at > > the end of the file. > > > > /data33 49 > > /data34 114 > > /data33 114 > > /data33 and /data44 simultaneously 78 and 59 respectively > > /data33 76 > > /data33 68 > > /data34 114 > > /data34 96 > > /data34 69 > > /data34 74 > > /data33 118 > > /data33 40 > > /data34 91 > > > > After remounting both filesystems: > > > > /data34 148 > > /data33 120 > > /data34 120 > > /data33 82 > > > > > > After unregistering the cache > > > > /data33 65 > > /data34 83 > > /data33 99 > > /data34 113 > > > > Cheers, > > Franco > > > > > > -- > > 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 -- 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
