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
