On Wednesday 13 December 2006 15:57, Gabriele Bulfon wrote: > I came across the performance problem with SPARC Sun280R machines, at first, because they have a slower processor then modern AMD or x86 machines. > On sparc machines large backups cannot be managed, because the transfer rate of the LTO is slowed down up to 1Mb/s or lower, because of the slow performance of Postgres on the same machine.
I don't think that the performance of the tape writing speed has anything to do with the database speed. This is because the big and slow part of the database update is done only *after* all the data for a job is written to the tape. If the database is indeed slowing down the tape writing, then it is because you have an under configured machine (slow CPU or lack of sufficient memory). > Moving the DB on another x86 / amd machine solve the problem, but I anyway can reach a maximum rate of 8-10Mb/sec, that is not the maximum transfer rate I may have on those LTO drives (that may run from 15 to 60 to 120 Mb/s depending on the version). Try moving your tape drive to a "modern AMD or x86 machine" :-) > On x86/amd machines, the transfer is higher and acceptable, but yet not using the full potential of the scsi library or tape drive, that is anyway lower than it may be, always because postgres is slowing down the bacula process. > I am happy to know that we're gonna have a release with transactions, and see what happens. It will enormously speed up the total time it takes to run a job. > Thanx a lot, > Gabriele. > Gabriele Bulfon - Sonicle S.r.l. > Tel +39 028246016 Int. 30 - Fax +39 028243880 > Via Felice Cavallotti 16 - 20089, Rozzano - Milano - ITALY > http://www.sonicle.com > ---------------------------------------------------------------------------------- > Da: Bill Moran <[EMAIL PROTECTED]> > A: Gabriele Bulfon <[EMAIL PROTECTED]> > Cc: bacula-users@lists.sourceforge.net > Data: 13 dicembre 2006 15.09.50 CET > Oggetto: Re: [Bacula-users] Postgres slow because of autocommit > In response to Gabriele Bulfon <[EMAIL PROTECTED]>: > > Hello, > > I stumbled upon some pages that confirm a suspect I had about using > > postgres with bacula: > > - Postgres has autocommit by default, slowing down a lot any Bacula > > operation because Bacula does not use any transaction during write. > > If this is true....do I have any way to set up just the Bacula database > > (not the other ones I have) to have no autocommit? > > Is there any "pre-script" to set the bacula connection without auto commit? > There is no way (that I'm aware of) to disable "autocommit". > By definition, any database that's not being fed transactions is in > "autocommit" mode (PostgreSQL actually calls this "unchained" mode). > It makes sense: without an explicit transaction, how would the DB > server know when to commit the data? I don't know of any DB that > does it any differently. > That being said, the Bacula team has been working hard at adding > transaction support and other performance improvements -- if you > search the list archives, you'll see lots of discussions. I think > some of the improvements are slated to appear in the next version. > That being said, PostgreSQL runs just fine even without the transactions. > Everything I run uses PostgreSQL (I manage 4 directors). Two of them > manage large data sets using beefy hardware (of 25 servers, 1 of them > has 1,500,000 files/12G compressed) Another one is my laptop, and the > fourth is a medium-grade machine backing up about 20G of servers and > desktops. None of them are experiencing any performance problems. > -- > Bill Moran > Collaborative Fusion Inc. > [EMAIL PROTECTED] > Phone: 412-422-3463x4023 > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
