Hi! I lost bcache device after a reboot and dmesg contains the following: [ 26.991085] bcache: prio_read() bad csum reading priorities [ 26.991088] bcache: prio_read() bad magic reading priorities [ 26.991425] attempt to access beyond end of device [ 26.991428] sdc: rw=48, want=3405010361836132352, limit=468862128 [ 26.991430] bcache: error on 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27: accessing priorities, disabling caching how to fix it? i am using the following fix (recreate cache device with the old cuid) and it works till next reboot. # bcache-super-show /dev/sdc sb.magic ok sb.first_sector 8 [match] sb.csum F19B35ED4C357841 [match] sb.version 3 [cache device] dev.label (empty) dev.uuid 7dddbf16-ca58-48e3-82d8-da47ae7726dc dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.cache.first_sector 1024 dev.cache.cache_sectors 468860928 dev.cache.total_sectors 468861952 dev.cache.ordered yes dev.cache.discard no dev.cache.pos 0 dev.cache.replacement 0 [lru] cset.uuid 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 # make-bcache -C --cset-uuid 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 /dev/sdc Already a bcache device on /dev/sdc, overwrite with --wipe-bcache make-bcache -C --wipe-bcache --cset-uuid 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 /dev/sdc Device /dev/sdc already has a non-bcache superblock, remove it using wipefs and wipefs -a # wipefs -a /dev/sdc # make-bcache -C --wipe-bcache --cset-uuid 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 /dev/sdc UUID: f7d97543-69ea-4636-a4ff-ab925ab5abdd Set UUID: 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 version: 0 nbuckets: 457873 block_size: 1 bucket_size: 1024 nr_in_set: 1 nr_this_dev: 0 first_bucket: 1 # echo /dev/sdc > /sys/fs/bcache/register dmesg: [42999.742342] bcache: run_cache_set() invalidating existing data [42999.900046] bcache: bch_cached_dev_attach() Caching md0 as bcache0 on set 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 [42999.900067] bcache: register_cache() registered cache device sdc [43002.019693] EXT4-fs (bcache0): recovery complete [43002.043362] EXT4-fs (bcache0): mounted filesystem with ordered data mode. Opts: discard,errors=remount-ro and final steps: # echo writethrough > /sys/block/bcache0/bcache/cache_mode # echo 128k > /sys/block/bcache0/bcache/sequential_cutoff # ./bcache-status -s --- bcache --- Device /dev/bcache0 (251:0) UUID 4ca0fbc9-d20b-4a3d-bbd1-38d9a5810c27 Block Size 0.50KiB Bucket Size 512.00KiB Congested? False Read Congestion 2.0ms Write Congestion 20.0ms Total Cache Size 223.57GiB Total Cache Used 2.24GiB (0%) Total Cache Unused 221.34GiB (99%) Dirty Data 0B (0%) Evictable Cache 223.57GiB (100%) Replacement Policy [lru] fifo random Cache Mode [writethrough] writeback writearound none Total Hits 139 (3%) Total Misses 3816 Total Bypass Hits 0 Total Bypass Misses 0 Total Bypassed 0B --- Backing Device --- Device /dev/md0 (9:0) Size 5.46TiB Cache Mode [writethrough] writeback writearound none Readahead 0 Sequential Cutoff 128.00KiB Merge sequential? False State clean Writeback? True Dirty Data 0B Total Hits 139 (3%) Total Misses 3816 Total Bypass Hits 0 Total Bypass Misses 0 Total Bypassed 0B --- Cache Device --- Device /dev/sdc (8:32) Size 223.57GiB Block Size 0.50KiB Bucket Size 512.00KiB Replacement Policy [lru] fifo random Discard? False I/O Errors 0 Metadata Written 1.60MiB Data Written 19.20MiB Buckets 457873 Cache Used 2.24GiB (0%) Cache Unused 221.34GiB (99%) -- 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
