I’d like to provide access to past file versions to users over Samba (with native windows interface), unfortunately, for this to work, the files need not to be in a singe FS image.

As such, with a dump consisting of about a quater milion of files. Making a copy (snapshot) takes close to 16h on my hardware (and that is with data and metadata on thee different disks including one RAID0).

I’m not certain about the numbers, but in this use case, current btrfs with compression-force and native FS snapshots beats lessfs in disk usage at about 6-10 snapshots. Maybe a bit later.
Now I have over 8 months of daily rdiff-backup snapshots and I’d like to keep ‘em…

What’s more rdiff from server to lessfs machine takes about 4h, with btrfs… 17 minutes.

No fancy tuning of either lessfs or one of the other filesystems.
I hope to find time to upload the lessfs-1.2.2.2 release today.

The used lessfs.cfg file is this:

# Enable informational messages about compression.
DEBUG = 5
HASHNAME=MHASH_TIGER192
#HASHNAME=MHASH_SHA256
# The (chopped) hashlen in bytes, minimum is 20.
HASHLEN = 24
BLOCKDATA_IO_TYPE=file_io
BLOCKDATA_PATH=/data/dta/blockdata.dta
#BLOCKDATA_PATH=/data/mta
#BLOCKDATA_BS=1048576
#
BLOCKUSAGE_PATH=/data/mta
BLOCKUSAGE_BS=1048576
#
DIRENT_PATH=/data/mta
DIRENT_BS=1048576
#
FILEBLOCK_PATH=/data/mta
FILEBLOCK_BS=1048576
#
META_PATH=/data/mta
META_BS=1048576
HARDLINK_PATH=/data/mta
HARDLINK_BS=1048576
#
SYMLINK_PATH=/data/mta
SYMLINK_BS=1048576
#
# The freelist database is only used
# with the file_io backend
#
FREELIST_PATH=/data/mta
FREELIST_BS=1048576
#
# CACHESIZE in MB
CACHESIZE=512
# Flush data to disk after X seconds.
COMMIT_INTERVAL=15
#
LISTEN_IP=127.0.0.1
LISTEN_PORT=100
# Not more then 2 on most machines.
MAX_THREADS=32
#DYNAMIC_DEFRAGMENTATION on or off, default is off.
DYNAMIC_DEFRAGMENTATION=on
COREDUMPSIZE=2560000000
# Consider SYNC_RELAX=1 or SYNC_RELAX=2 when exporting lessfs with NFS.
SYNC_RELAX=0
# When BACKGROUND_DELETE=on lessfs will spawn a thread to delete
# a file as a background task. This is a recently added feature
# and is therefore disabled by default.
BACKGROUND_DELETE=on
# Requires openssl and lessfs has to be configured with –with-crypto
ENCRYPT_DATA=off
# ENCRYPT_META on or off, default is off
# Requires ENCRYPT_DATA=on and is otherwise ignored.
ENCRYPT_META=on
# You don’t like fsck?
ENABLE_TRANSACTIONS=on
# Select a blocksize to fit your needs.
BLKSIZE=131072
COMPRESSION=qlz
MIN_SPACE_FREE=10
STICKY_ON_LOCKED=on