Like focal, bcache device was setup: root@buneary:/tmp# ls -l /dev/bcache0 brw-rw---- 1 root disk 252, 0 Apr 1 22:35 /dev/bcache0 root@buneary:/tmp# ls -l /dev/sdb1 brw-rw---- 1 root disk 8, 17 Apr 1 23:59 /dev/sdb1 lsb_release -a -------------- Distributor ID: Ubuntu Description: Ubuntu 20.10 Release: 20.10 Codename: groovy dpkg -l | grep sosreport ii sosreport 4.1-1ubuntu0.20.10.1 amd64 Set of tools to gather troubleshooting data from a system Genearated sosreport contains relevant bcache files: root@buneary:/tmp/sosreport-buneary-bcache-groovy-2021-04-01-cduinfr/sys/fs/bcache/d271b67f-43b3-4b21-b6e6-7dba9eb1410e# ll total 60 drwxr-xr-x 7 root root 4096 Apr 1 23:38 ./ drwxr-xr-x 3 root root 4096 Apr 1 22:34 ../ -r--r--r-- 1 root root 5 Apr 1 23:59 average_key_size lrwxrwxrwx 1 root root 141 Apr 1 23:59 bdev0 -> ../../../devices/pci0000:00/0000:00:01.0/0000:03:00.0/host0/scsi_host/host0/port-0:3/end_device-0:3/target0:0:2/0:0:2:0/block/sdb/sdb1/bcache/ -r--r--r-- 1 root root 5 Apr 1 23:59 block_size -r--r--r-- 1 root root 7 Apr 1 23:59 bucket_size -r--r--r-- 1 root root 4 Apr 1 23:59 cache_available_percent -rw-r--r-- 1 root root 5 Apr 1 23:59 congested_read_threshold_us -rw-r--r-- 1 root root 6 Apr 1 23:59 congested_write_threshold_us drwxr-xr-x 2 root root 4096 Apr 1 23:59 internal/ drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_day/ drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_five_minute/ drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_hour/ drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_total/ -r--r--r-- 1 root root 2 Apr 1 23:59 tree_depth root@buneary:/tmp/sosreport-buneary-bcache-groovy-2021-04-01-cduinfr/sys/block/bcache0# ls -l total 84 -r--r--r-- 1 root root 2 Apr 1 23:59 alignment_offset lrwxrwxrwx 1 root root 133 Apr 1 23:59 bcache -> ../../../pci0000:00/0000:00:01.0/0000:03:00.0/host0/scsi_host/host0/port-0:3/end_device-0:3/target0:0:2/0:0:2:0/block/sdb/sdb1/bcache lrwxrwxrwx 1 root root 15 Apr 1 22:34 bdi -> ../../bdi/252:0 -r--r--r-- 1 root root 3 Apr 1 23:59 capability -r--r--r-- 1 root root 6 Apr 1 22:35 dev -r--r--r-- 1 root root 2 Apr 1 23:59 discard_alignment -r--r--r-- 1 root root 0 Apr 1 23:59 events -r--r--r-- 1 root root 0 Apr 1 23:59 events_async -rw-r--r-- 1 root root 3 Apr 1 23:59 events_poll_msecs -r--r--r-- 1 root root 4 Apr 1 23:59 ext_range -r--r--r-- 1 root root 2 Apr 1 22:35 hidden drwxr-xr-x 2 root root 4096 Apr 1 22:35 holders -r--r--r-- 1 root root 18 Apr 1 23:59 inflight drwxr-xr-x 2 root root 4096 Apr 1 23:59 integrity drwxr-xr-x 2 root root 4096 Apr 1 23:59 power drwxr-xr-x 2 root root 4096 Apr 1 23:59 queue -r--r--r-- 1 root root 4 Apr 1 23:59 range -r--r--r-- 1 root root 2 Apr 1 23:59 removable -r--r--r-- 1 root root 2 Apr 1 23:59 ro -r--r--r-- 1 root root 11 Apr 1 22:35 size drwxr-xr-x 2 root root 4096 Apr 1 22:34 slaves -r--r--r-- 1 root root 153 Apr 1 23:59 stat lrwxrwxrwx 1 root root 23 Apr 1 22:33 subsystem -> ../../../../class/block drwxr-xr-x 2 root root 4096 Apr 1 23:59 trace -rw-r--r-- 1 root root 47 Apr 1 22:34 uevent root@buneary:/tmp/sosreport-buneary-bcache-groovy-2021-04-01-cduinfr/sys/block/bcache0# cd bcache root@buneary:/tmp/sosreport-buneary-bcache-groovy-2021-04-01-cduinfr/sys/block/bcache0/bcache# ls -l total 128 --w------- 1 root root 0 Apr 1 23:59 attach -r--r--r-- 1 root root 5 Apr 1 23:59 backing_dev_name -r--r--r-- 1 root root 37 Apr 1 23:59 backing_dev_uuid lrwxrwxrwx 1 root root 91 Apr 1 23:38 cache -> ../../../../../../../../../../../../../../../fs/bcache/d271b67f-43b3-4b21-b6e6-7dba9eb1410e -rw-r--r-- 1 root root 42 Apr 1 23:59 cache_mode --w------- 1 root root 0 Apr 1 23:59 clear_stats --w------- 1 root root 0 Apr 1 23:59 detach lrwxrwxrwx 1 root root 63 Apr 1 22:34 dev -> ../../../../../../../../../../../../../../virtual/block/bcache0 -r--r--r-- 1 root root 5 Apr 1 23:59 dirty_data -rw-r--r-- 1 root root 2 Apr 1 23:59 io_disable -rw-r--r-- 1 root root 3 Apr 1 23:59 io_error_limit -r--r--r-- 1 root root 2 Apr 1 23:59 io_errors -rw-r--r-- 1 root root 1 Apr 1 23:59 label -r--r--r-- 1 root root 2 Apr 1 23:59 partial_stripes_expensive -rw-r--r-- 1 root root 5 Apr 1 23:59 readahead -rw-r--r-- 1 root root 16 Apr 1 23:59 readahead_cache_policy -rw-r--r-- 1 root root 2 Apr 1 23:59 running -rw-r--r-- 1 root root 5 Apr 1 23:59 sequential_cutoff -r--r--r-- 1 root root 6 Apr 1 23:59 state drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_day drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_five_minute drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_hour drwxr-xr-x 2 root root 4096 Apr 1 23:59 stats_total --w------- 1 root root 0 Apr 1 23:59 stop -rw-r--r-- 1 root root 14 Apr 1 23:59 stop_when_cache_set_failed -r--r--r-- 1 root root 5 Apr 1 23:59 stripe_size -rw-r--r-- 1 root root 3 Apr 1 23:59 writeback_delay -rw-r--r-- 1 root root 2 Apr 1 23:59 writeback_metadata -rw-r--r-- 1 root root 3 Apr 1 23:59 writeback_percent -rw-r--r-- 1 root root 7 Apr 1 23:59 writeback_rate -r--r--r-- 1 root root 117 Apr 1 23:59 writeback_rate_debug -rw-r--r-- 1 root root 6 Apr 1 23:59 writeback_rate_i_term_inverse -rw-r--r-- 1 root root 2 Apr 1 23:59 writeback_rate_minimum -rw-r--r-- 1 root root 3 Apr 1 23:59 writeback_rate_p_term_inverse -rw-r--r-- 1 root root 2 Apr 1 23:59 writeback_rate_update_seconds -rw-r--r-- 1 root root 2 Apr 1 23:59 writeback_running root@buneary:/tmp/sosreport-buneary-bcache-groovy-2021-04-01-cduinfr/sys/block/bcache0/bcache# cat cache_mode [writethrough] writeback writearound none