On Thu, 27 Jul 2006, Emery Guevremont wrote: >> At least, spooling should guarantee that your tape drive is able to run at >> full speed continuosly. If for some reason your system isn't able to supply >> data to the tape drive at fast enough rate, the drive keeps >> stopping-repositioning-writing-stopping again, which then takes extra time >> and causes extra wear to the drive and the tape. > > How sure are you that it continuously writes to tape.
When it is flushing the spool then it will be writing continuously(*) > On my setup I put a max spooling size of 10 Gigs, and everytime it > reaches the 10 gigs, the spooling seems to stop. Bacula seems to empty > the spool by writing it to tape. Once the spool has been emptied, the > backup process (the transfering over the network the data) continues > again until the spool reaches once again 10G. The tape is either stopped, or running at full speed. What it is _not_ doing, is shoeshining (rapid back and forth motions) as data is written in slowly. > In my case I'm not sure I have the best setup possible for speed. Spooling gives you the ability to have concurrent backups running - that's a real win - but ONLY as long as the spool disk is fast enough to handle simultanous read/writes (it really needs to benchmark at least twice as fast as the tape drive - and as fast again for every tape drive being serviced) AB ------------------------------------------------------------------------- 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
