Lessfs-0.9.0 is available for download.

This version of lessfs passes all the fsx-linux tests. It has been confirmed that this release fixes the problems that people where reporting with rsync.

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14 Responses to Lessfs-0.9.0 is available for download.

  1. Alex says:

    Good news ! Let’s try it now (gotta update my setup ) :p way to 1.0 is coming !

  2. Alex says:

    Oups, no files available on sourceforge for now ;) … i’ll take a look later…

  3. Very good news!!! Many thanks guys
    I have a stupid question but i need some clarification from some expert.
    I have tested the lessfs for a while with some backup or simple copy of file and if im not wrong the result is not so much good. As i understand the problem is related to TAR or other compress tool and the way create the block data, but how we can have very good Dedup factor using lessfs?
    Many thanks for possible help/solution/suggest

    • maru says:

      You have a view options:
      1. Use cp or rsync instead of tar.
      2. Patch tar so that new files are aligned with the blocksize of lessfs.
      3. Switch to disk image (whole disk or partitions) based backup.

  4. Areq says:

    What about snapshot ? Manny people really need and waiting for this important for backup process feature.

    • maru says:

      snapshots and replication will come in lessfs-2.0
      The focus for now is to release lessfs-1.0 stable if possible before the end of this year.

      Development of 2.0 will start early next year.


      • Areq says:

        I suspect that the implementation of snapshots will not be quick and easy. Enough at the beginning will be quick way to copy the entire directory tree under lessfs

        cp-a backup-2009-12-02 backup-2009-12-03
        is very slow now

        • maru says:

          Easy might not be the appropriate term. ;-)
          For now you can use lvm snapshots with the lessfs freeze command.

          You first freeze lessfs and then create a lvm snapshot.
          With the help of drbd you can implement replication.

          I hope this helps,


          • Areq says:

            but lvm snapshot gives significant performce degradation

            Currently I’am doing in this way:

            rsync -vax s1::/ /mnt/lessfs/s1_last
            cp -a /mnt/lessfs/s1_lat /mnt/lessfs/s1_`date +%s`

            but normal cp is slow, because must unpack all files from lessfs, check deduplication and update directory structure.

            I’m dreaming of sth like lessfscp – with can update only directory structure without touching data part.

          • maru says:

            Instead of cp -a /mnt/lessfs/s1_last /mnt/lessfs/s1_`date +%s` why don’t you

            mv /mnt/lessfs/s1_last /mnt/lessfs/s1_`date +%s`
            mkdir /mnt/lessfs/s1_last

            Moving a directory does hardly take time at all.


          • Areq says:

            mv /mnt/lessfs/s1_last /mnt/lessfs/s1_`date +%s` mkdir /mnt/lessfs/s1_last

            isn’t solution for me. I need few independent “full copy” of server in separate directory – one dir = one full backup

            I try to avoid coping via rsync all files every time
            (slow WAN connection)

  5. Hi Maru
    many thanks for your suggest, i never use lessfs with this method!! My first idea was use in comination of Bacula Backup and LinuxVTL (the Media emulate from LinuxVTL are store on LessFs) but i dont have so big advantage, i supposed for the tar problem.
    But where i can found Patched TAR? how is used RSync with dedup?
    Many thanks for help

    • maru says:

      The Bacula Guys should know how to fix this. Some commercial VTL vendors do smart things with the incoming data streams before they store them on a dedup filesystem.

      You can imagine that this is very complex because every vendor has it’s own proprietary way to store the data.

      I can take a look at tar but don’t hold your breath.

      Many people use rsync for backups:


      • Hi Maru
        Yes i know rsync but this tool dont suffer of the same TAR problem (shifting chunk)? Also an integration with a Backup solution like Bacula is very good way to manage small/medium office PC (simple way to restore a data using gui).
        So do you think is possible to patch Bacula Backup format for lessfs (dedup friendly)?
        Many thanks

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