My scenario:

Alfter installing lessfs I copy to /fuse

But after finish disk still have high load.
After waiting about 3 hours I’ve tied to unmount /fuse but this tirectory was still.
I’ve kill lessfs process and restart server.

After restart and mounting lessfs again use disk. (and this process won’t stop)

From logs
FILE lib_common.c – LINE 3827 – PID 21935 : Wed Mar 28 13:57:18 2012 – offset_to_mfreeblock : failed to find mbytes 231 – offset 0 – descriptor 230
FILE lib_bdb.c – LINE 104 – PID 21935 : Wed Mar 28 13:57:18 2012 – bdb_lock : btsearch_keyval
FILE lib_bdb.c – LINE 119 – PID 21935 : Wed Mar 28 13:57:18 2012 – bdb_lockedby : btsearch_keyval
FILE lib_bdb.c – LINE 1558 – PID 21935 : Wed Mar 28 13:57:18 2012 – btsearch_keyval : get DB_GET_BOTH BDB0073 DB_NOTFOUND: No matching key/data pair found
FILE lib_common.c – LINE 3827 – PID 21935 : Wed Mar 28 13:57:18 2012 – offset_to_mfreeblock : failed to find mbytes 231 – offset 0 – descriptor 230
FILE lib_common.c – LINE 198 – PID 21935 : Wed Mar 28 13:57:18 2012 – optimize_file : descriptor 229 base 230 mbytes 117760
FILE lib_bdb.c – LINE 974 – PID 21935 : Wed Mar 28 13:57:18 2012 – get_sorted_offsets : 230 descriptor 229
FILE lib_bdb.c – LINE 104 – PID 21935 : Wed Mar 28 13:57:18 2012 – bdb_lock : get_sorted_offsets
FILE lib_bdb.c – LINE 119 – PID 21935 : Wed Mar 28 13:57:18 2012 – bdb_lockedby : get_sorted_offsets
FILE lib_bdb.c – LINE 1018 – PID 21935 : Wed Mar 28 13:57:18 2012 – get_sorted_offsets : found 0 : count 1
FILE lib_bdb.c – LINE 1018 – PID 21935 : Wed Mar 28 13:57:18 2012 – get_sorted_offsets : found 0 : count 2

What lessfs do all this time? Can I disable DYNAMIC_DEFRAGMENTATION and BACKGROUND_DELETE after remounting filesystem?

# Enable informational messages about compression.
DEBUG = 1
HASHNAME=MHASH_TIGER192
#HASHNAME=MHASH_SHA256
# The (chopped) hashlen in bytes, minimum is 20.
HASHLEN = 24
BLOCKDATA_IO_TYPE=multifile_io
BLOCKDATA_PATH=/data_multi/dta/blockdata.dta
#
META_PATH=/data_multi/mta
META_BS=1048576
#
CACHESIZE=512
# Flush data to disk after X seconds.
COMMIT_INTERVAL=10
#
LISTEN_IP=127.0.0.1
LISTEN_PORT=100
# Not more then 2 on most machines.
MAX_THREADS=4
#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=off
# You don’t like fsck?
ENABLE_TRANSACTIONS=on
# Select a blocksize to fit your needs.
BLKSIZE=131072
COMPRESSION=lz4
TUNEFORSPEED=yes

Linux debian6
BDB-5.3

Linux version: Linux host 3.0.8 #1 SMP Mon Dec 26 18:58:59 CET 2011 x86_64 GNU/Linux
Lessfs version: 1.5.9

Lessfs mount options:
# /usr/bin/lessfs /volDedupe8.conf /mnt/volDedupe8 -d -f -o intr,default_permissions,use_ino,readdir_ino,allow_other,big_writes,max_read=131072,max_write=131072

Problem description:
1. # dd if=/dev/zero of=/mnt/volDedupe8/test4.dat bs=1M count=1000
2. In a couple of seconds, press CTRL+C
3. # ls -l /mnt/volDedupe8/. The response is “Transport endpoint is not connected”

Normally if i do not press CTRL+C, the error is not appear.

Lessfs debug:

allow_other,big_writes,max_read=131072,max_write=131072
FUSE library version: 2.8.4
nullpath_ok: 0
unique: 1, opcode: INIT (26), nodeid: 0, insize: 56
INIT: 7.16
flags=0x0000007b
max_readahead=0x00020000
INIT: 7.12
flags=0x00000031
max_readahead=0x00000080
max_write=0x00010000
unique: 1, success, outsize: 40
unique: 2, opcode: STATFS (17), nodeid: 1, insize: 40
statfs /
unique: 2, success, outsize: 96
unique: 3, opcode: STATFS (17), nodeid: 1, insize: 40
statfs /
unique: 3, success, outsize: 96
unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 56
getattr /
unique: 4, success, outsize: 120
unique: 5, opcode: LOOKUP (1), nodeid: 1, insize: 50
LOOKUP /test4.dat
getattr /test4.dat
NODEID: 2
unique: 5, success, outsize: 144
unique: 6, opcode: OPEN (14), nodeid: 2, insize: 48
open flags: 0x8001 /test4.dat
open[110] flags: 0x8001 /test4.dat
unique: 6, success, outsize: 32
unique: 7, opcode: SETATTR (4), nodeid: 2, insize: 128
truncate /test4.dat 0
unique: 8, opcode: INTERRUPT (36), nodeid: 0, insize: 48
INTERRUPT: 7
Segmentation fault (`core’ generado)