Thomas Mueller schrieb: > > >> > 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. > > > > With > > > > Maximum File Size = 5G > > Maximum Block Size = 262144 > > Maximum Network Buffer Size = 262144 > > > > I get up to 150M MB/s while despooling to LTO-4 drives. Maximum File > > Size gave me some extra MB/s, I think it's as important as the Maximum > > Block Size. > > > > thanks for providing this hints. just searching why my lto-4 is writing > just at 40mb/s. will try them out! > > searching the "Maximum File Size" in the manual I found this: > > If you are configuring an LTO-3 or LTO-4 tape, you probably will want to > set the Maximum File Size to 2GB to avoid making the drive stop to write > an EOF mark. > > maybe this is the reason for the "extra mb/s".
Modifying the Maximum Block Size to more than 262144 didn't change much here. But changing the File Size did. Much. Anyway, 40 MB/s seems a bit low, even with the defaults. Before tuning our setup I got ~75 MB/s. Are you spooling the data to disk or writing directly to tape? Ralf ------------------------------------------------------------------------------ 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