Zitat von lst_ho...@kwsoft.de: > Zitat von Nils Juergens <nils+bac...@muon.de>: > >> Hello Andreas, >> >> Am 20.08.2012 17:29, schrieb lst_ho...@kwsoft.de:> As the tape is >> altering speed all the time with Bacula i would like to >>> know if there is a possibility to get closer to the dd values and what >>> could be the bottleneck in such a setup? >> >> for me (with LTO-3) increasing Maximum block size has had quite the >> impact on performance. >> >> Sadly, with the new setting I had trouble reading my tapes so switched >> back to the old configuration. >> >> I suspect you may get around the problem if you re-label all your tapes >> after switching the block size, however I have not testet this. Maybe >> someone can shed some light on the whole block size business? :-) > > Would really nice indeed. As far as i understand the block size used > as default (and max.) if nothing is specified is 64,512 Bytes. This > looks a little bit low for high-speed tape and i'm not sure what the > downside of higher values could be or why the manual state that there > is no need to set it explicit (higher). > As i'm in the testing phase i will have a look if higher values lead > to any trouble. Anyone aware why the default of 126*512 Bytes was > choosen? >
Some short tests with the "Maximum Block Size" set, show transfer speed to the LTO-4 of 87MBytes/sec with 256K and 98MBytes/sec with 1M with Bacula encrypted data, so with this we are reaching the theoretical uncompressed speed of the LTO-4 device by ~20%. It would be really helpful if there is some developer to say if there is any downside of large block sizes? Regards Andreas ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
