Dan Langille wrote (2016/03/13): > > As well as increasing max file size you need to boost the tape buffer size > > from the 64kB default. I use 2MB > > This is a hardware setting?
Hello, it is software settings: * Increasing max file size is "Maximum File Size". I use 16 GB for LTO-5 and for LTO-4 it should be similar. Every file mark means delay of several seconds (3-5?), so you can count, how big slow down for each file size it is in percents. On the other side, too big file size means slower seeks. * Tape buffer size: It is "Maximum Block Size". It seems that in Linux it is a must to increase it. However, in FreeBSD, I have no problems with default 65536 bytes, where I have seen speeds over 250 MB/s with well compressable datas and without notable system load, so I did not increase it yet. For check, how big block you can use, try mt status -v. It is smaller of maxio and cpi_maxio. Without kernel patching, you could certainly use 131072 bytes. However, maxio could be increased easily (MAXPHYS kernel option) and cpi_maxio depends on driver, how well the value is obtained. Sometimes it is just a constant, which is known that it could be increased. But, I still think that it is not needed so much in FreeBSD. -- Rudolf Cejka <cejkar at fit.vutbr.cz> http://www.fit.vutbr.cz/~cejkar Brno University of Technology, Faculty of Information Technology Bozetechova 2, 612 66 Brno, Czech Republic ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
