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![Make it faster
➢ You have multiple options for compression
# cd /sys/fs/bcachefs/UUID/options
# cat background_compression
[none] lz4 gzip zstd
➢ Documentation states to avoid zstd for now
➢ also keep in mind block alignment](https://cdn.statically.io/img/image.slidesharecdn.com/improveyourstoragewithbcachefs-210815080550/75/Improve-your-storage-with-bcachefs-34-2048.jpg)
Uploaded byMarian Marinov
Improve your storage with bcachefs
Marian Marinov shares his experience in upgrading home storage from HDDs to SSDs and introduces bcache and bcachefs, a unified file system that enhances storage performance. He highlights the features of bcachefs, including copy-on-write, data checksumming, and replication, while providing practical instructions for setup and management. The document concludes with technical insights and commands for using bcachefs effectively.
Improve your storage with bcachefs
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- 3. I want toshare a story...
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- 5. ➢ 2 yearsago I upgraded my home storage
- 6. ➢ 2 yearsago I upgraded my home storage ➢ from all HDD to all SSD drives
- 7. you all canspeculate as to why I did that
- 8. Let's take alook at how HDD work
- 9. Let's take alook at how HDD work Platters
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- 13. Optimization ➢ File systemstried to optimize for this inefficiency
- 14. Optimization ➢ File systemstried to optimize for this inefficiency ➢ write contents of the files within the same cylinder ➢ utilizing the space under the heads on all platters
- 15. Optimization ➢ File systemstried to optimize for this inefficiency ➢ write contents of the files within the same cylinder ➢ utilizing the space under the heads on all platters ➢ continue the writes on to next sector (try not to skip any, reducing fragmentation)
- 16. Optimization ➢ File systemstried to optimize for this inefficiency ➢ write contents of the files within the same cylinder ➢ utilizing the space under the heads on all platters ➢ continue the writes on to next sector (try not to skip any, reducing fragmentation) ➢ continue directly on to the next track
- 17. Optimization ➢ File systemstried to optimize for this inefficiency ➢ The Linux kernel tried to optimize the reads and writes ➢ read-ahead ➢ combine and order the writes
- 18. Optimization ➢ File systemstried to optimize for this inefficiency ➢ The Linux kernel tried to optimize the reads and writes ➢ Storage controllers ➢ write-behind with BBU
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- 20. Oh NO, thisis not bcachefs Now comes bcache
- 22. ➢ Its 2011and StorPool are just starting ➢ A guy named Kent Overstreet ➢ SSD booming ➢ Storage vendors starting to offer things like ➢ cachecade ➢ cachevault ➢ etc.
- 23. Bcache is born ➢Bcache is simple block level cache ➢ 2013 it is included in kernel 3.10 ➢ It has some bugs :)
- 24. Bcache ➢ Bcache isthe ground work for bcachefs ➢ It only knows about the blocks, but not their use ➢ It orders the writes so the backing rotational disk will do more sequential writes
- 25. Finally bcachefs bcachefs wasborn in 2014-2015 ➢current features ➢ Copy on write (COW) - like zfs or btrfs ➢ Full data checksumming ➢ Caching ➢ Compression (LZ4,ZSTD,) ➢ Replication (RAID1/10)
- 26. The juicy details AVGMIN MAX sw raid1 86 80 93 MB/s bcachefs (1) 93 90 97 MB/s bcachefs (2) 123 118 128 MB/s 36 38 25 1. bcachefs with only rotational HDDs 2. bcachefs with SSD backed device dd if=/dev/zero of=test$i oflag=direct count=200 bs=5M
- 27. Fun facts root@firefly:~# mount/dev/sdc1 /bcache/ root@firefly:~# df -h /bcache Filesystem Size Used Avail Use% Mounted on /dev/sdc1 639G 1.3M 629G 1% /bcache root@firefly:~# bcachefs device add --group=hdd1 /bcache /dev/sdd1 root@firefly:~# df -h /bcache Filesystem Size Used Avail Use% Mounted on /dev/sdc1:/dev/dev-1 1.3T 1.3M 1.3T 1% /bcache root@firefly:~# bcachefs device add --group=hdd1 /bcache /dev/sde1 root@firefly:~# bcachefs device add --group=hdd1 /bcache /dev/sdf1 root@firefly:~# df -h /bcache Filesystem Size Used Avail Use% Mounted on /dev/sdc1:/dev/dev-1:/dev/dev-2:/dev/dev-3 2.6T 1.5M 2.5T 1% /bcache
- 28. Fun facts root@firefly:~# mount/dev/sdc1 /bcache/ root@firefly:~# df -h /bcache Filesystem Size Used Avail Use% Mounted on /dev/sdc1 639G 1.3M 629G 1% /bcache root@firefly:~# bcachefs device add --group=hdd1 /bcache /dev/sdd1 root@firefly:~# df -h /bcache Filesystem Size Used Avail Use% Mounted on /dev/sdc1:/dev/dev-1 1.3T 1.3M 1.3T 1% /bcache root@firefly:~# bcachefs device add --group=hdd1 /bcache /dev/sde1 root@firefly:~# bcachefs device add --group=hdd1 /bcache /dev/sdf1 root@firefly:~# df -h /bcache Filesystem Size Used Avail Use% Mounted on /dev/sdc1:/dev/dev-1:/dev/dev-2:/dev/dev-3 2.6T 1.5M 2.5T 1% /bcache
- 29. Installation ➢ clone theirkernel and build it https://evilpiepirate.org/git/bcachefs.git ➢ clone bcachefs-tools and build them https://evilpiepirate.org/git/bcachefs-tools.git
- 30. First steps ➢ Prepareyour drives (as partitions or whole) ➢ bcachefs format /dev/sdc1 ➢ bcachefs format /dev/sdd1 ➢ bcachefs format /dev/sde ➢ bcachefs format /dev/sdf ➢ mount mount -t bcachefs /dev/sdc1:/dev/sdd1:/dev/sde:/dev/sdf /bcache
- 31. Make it faster ➢Let's assume sdb is our SSD drive # bcachefs format /dev/sdb # bcachefs device add --group=hdd2 /bcache /dev/sdb ➢ We still haven't done anything... # cd /sys/fs/bcachefs/UUID/options # echo hdd2 > promote_target # echo hdd2 > foreground_target # echo hdd2 > metadata_target
- 32. Make it faster ➢foreground_target ➢ writes are first cached here
- 33. Make it faster ➢foreground_target ➢ writes are first cached here ➢ promote_target ➢ reads are cached on this device
- 34. Make it faster ➢You have multiple options for compression # cd /sys/fs/bcachefs/UUID/options # cat background_compression [none] lz4 gzip zstd ➢ Documentation states to avoid zstd for now ➢ also keep in mind block alignment
- 35. Make it redundant ➢Make two copies of the data # cd /sys/fs/bcachefs/UUID/options # echo 2 > data_replicas # echo 2 > metadata_replicas
- 36. You can doit all at once # bcachefs format --group=ssd /dev/sdb --group=hdd /dev/sdc /dev/sdd /dev/sde /dev/sdf --data_replicas=2 --metadata_replicas=2 --foreground_target=ssd --background_target=hdd --promote_target=ssd # mount -t bcachefs /dev/sdb:/dev/sdc:/dev/sdd/dev/sde:/dev/sdf /mnt
- 37. Some management stuff ➢Remove a device # bcachefs device evacuate /dev/sdf1 # bcachefs device remove /dev/sdf1 # bcachefs device offline /dev/sdf1 ➢ Bring back a device # bcachefs device online /dev/sdf1 # bcachefs device add /dev/sdf1 ➢ Make sure all of your data is replicated # bcachefs data rereplicate /bcache/
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