On Tue, Jan 05, 2010 at 04:55:51PM -0500, John Drescher wrote: > >> I'm not seeing anywhere close to 60M/s ( < 30 ). I think I just fixed > >> that. I increased the block size to 1M, and that seemed to really > >> increase the throughput, in the test I just did. I will see tomorrow, > >> when it all runs. > > > > Yes, if you aren't already, whenever writing to tape you should almost > > without exception (and certainly on any modern tape drive) be using the > > largest block size that btape says your drive supports. > > I tried to do that years ago but I believe this made all tapes that > were already written to unreadable (and I now have 80) so I gave this > up. With my 5+ year old dual processor Opteron 248 server I get 25MB/s > to 45MB/s despools (which measures the actual tape rate) for my LTO2 > drives. The reason for the wide range seems to be compression.
Can anybody confirm or rebute this for 2.2.x? I'm currently fiddling with Maximum Block Size and a shiny new tape. It looks like 1M is too much for my tape drive, but 512K seems to work and it's making a huge difference: btape fill reports > 60 MB/s right at the beginning, then drops to abour 52 MB/s. Thanks, Tino. -- "What we nourish flourishes." - "Was wir nähren erblüht." www.lichtkreis-chemnitz.de www.tisc.de ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users