This version of lessfs introduces a new hash named Blue Midnight Whish.
This is a very fast hash that increases lessfs performance significantly. The implementation makes it easy to use any of the hashes from the NIST hash competition. BMW was choosen for lessfs because of the speed.
The length of the hash is now configurable between 20 and 32 bytes for BMW and 20 to 24 for the tiger hash.
Hi Mark
i usually make my test on the new version, and Wauu!! is very speed up compared to old version using TokioCab and default hash “24”.
for example i can write a file of 680922 kbyte in 47 sec but i notice a small slow down on reading dedup file, on old 0.6.1 i cp from deduped filesystem to ext3 mount point using a file of 680922 kbyte in 40 sec with lessfs 0.7.4 i need 63 sec. What do you think about?
I have another question about dedup algorith, what do you think about file based dedup? I ask it because i always supposed on dedup a way to backup lot of machine with same filesystem (same OS level) as a single backup, but from my test seems is not working as thought
… What do you think about?
Have you see this post (http://sourceforge.net/apps/wordpress/bacula/2009/10/06/block-deduplication-layer-for-the-storage-daemon/) on bacula site?
Many thanks for your great work!!!
Sincerely Dimitri
Hi Dimitri,
Thanks for testing the performance of this new release. I’ll do the same read performance test to see if I see the same performance degradation. The choice of hash should not make a difference when one is reading data from lessfs.
Mark.
B.T.W. I contacted the author of bacula to see if I can help to fix his problem.
Thanks for the link.
Hi Mark
many thanks for you effort, im pleased to help in the development of this project, if you need other test im glade to help you.
Many thanks and also thakns to help the bacula guys
Dimitri
Thank you very much for your good and hard work. I think we were missing somthing like that.
And I’m really glad and happy to read that Lessfs is being used to improve Bacula. I’m just now deploying Bacula at work, and I am testing how much good is Lessfs storing its volumes; some kind of deduplication integrated in Bacula could be a very good news !
Xavi