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Member "lessfs-1.7.0/README.berkeleydb" (30 Sep 2011, 2421 Bytes) of package /linux/misc/old/lessfs-1.7.0.tar.gz:


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    1 
    2       RELEASE NOTES FOR LESSFS + BERKELEYDB
    3 
    4 ---------------------------------------------------
    5 
    6 Howto build:
    7 
    8 Lessfs with BerkeleyDB requires a recent version
    9 of BerkeleyDB. It's tested with BerkeleyDB 4.8
   10 
   11 To build from source:
   12 Download BerkeleyDB 4.8
   13 tar xf db-4.8.30.tar.gz
   14 cd db-4.8.30
   15 cd build_unix/
   16 ../dist/configure
   17 make 
   18 make install
   19 
   20 Add /usr/local/BerkeleyDB.4.8/ to ld.so.conf
   21 
   22 tar xf lessfs-1.4.0.tar.gz
   23 cd lessfs-1.4.0
   24 export CFLAGS="-I /usr/local/BerkeleyDB.4.8/include/ -L /usr/local/BerkeleyDB.4.8/lib"
   25 ./configure --with-berkeleydb
   26 make
   27 make install
   28 cp etc/lessfs.cfg-bdb.cfg /etc/lessfs.cfg
   29 
   30 Change /etc/lessfs.cfg
   31 mklessfs -f -c /etc/lessfs.cfg
   32 lessfs /etc/lessfs.cfg /your/mountpoint
   33 
   34 ---
   35 
   36 Lessfs now supports BerkeleyDB next to tokyocabinet
   37 and hamsterdb. The decision to add BerkeleyDB was 
   38 taken because both tokyocabinet and hamsterdb failed
   39 to provide the reliability that is needed for the
   40 enterprise.
   41 
   42 Although BerkeleyDB is not the fastest of the three
   43 backends when used with a 128k blocksize the performance
   44 is acceptable. The reliability is very good, BerkeleyDB
   45 not only claims to be ACID but it really is very reliable
   46 when it comes to unexpected power downs and crashes.
   47 
   48 You can choose the degree of dataprotection that suits
   49 your needs by changing DB_CONFIG. Please take a look
   50 at the DB_CONFIG file in the lessfs distribution file.
   51 
   52 Do not use lessfs with berkeleydb without a DB_CONFIG file
   53 in the metadata directory!
   54 Should lessfs go down because of problems with BerkeleyDB
   55 it will generate a logfile which is defined in lib_bdb.h
   56 #define BERKELEYDB_ERRORLOG  "/var/log/lessfs-bdb_err.txt"
   57 
   58 A typical reason for a crash would be the absence of a
   59 DB_CONFIG file which will cause lessfs to run out of 
   60 bdb locks.
   61 
   62 # We really need these, my system uses approx 6000
   63 set_lk_max_locks   10000
   64 set_lk_max_lockers 10000
   65 set_lk_max_objects 10000
   66 
   67 When you add TUNEFORSPEED=yes to lessfs.cfg BerkeleyDB
   68 will be used with : DB_TXN_WRITE_NOSYNC
   69 and DB_TXN_NOSYNC | DB_TXN_NOWAIT
   70 
   71 This may increase the throughput of lessfs but it will
   72 increase the possibility of data loss!
   73 
   74 Since lessfs-1.4.0 the reuse of deleted data chunks is delayed
   75 to 10 * COMMIT_INTERVAL. This to ensure that whenever the system
   76 crashes and the database is reverted that no corruption will
   77 occur. When the database performs a rollback in time the actual data
   78 should not have been overwritten in the blockdata file.