Dimitri Maziuk wrote (2015/05/20): > Quoting quantum lto-6 sales blurb > (http://www.quantum.com/products/tapedrives/ltoultrium/lto-6/index.aspx) > > Fast backup and restore performance ?at speeds up to 400MB/s (1.4TB/hr)* > > * Assumes 2.5:1 compression for LTO-6, 2:1 for other LTO > > Assuming no compression = 400/2.5 = 160. > > > Seagate NAS drives have a max throughput ranging from 149MB/sec to > > 180MB/sec depending on capacity: > > > > http://www.seagate.com/www-content/product-content/nas-fam/nas-hdd/en-us/docs/nas-hdd-ds1789-3-1409gb.pdf > > 160 < 180. > > you get it now?
It should be "min. 160 < max. 180", which is false. Tape users usually do not want to switch off hardware tape drive compression and use slower/faster better/worse software compression instead of it. Also, max. disk speeds are just at the beginning of the disk. At the end, it is often just 1/3 to 2/3 of the max. speed. And when the disk is not new, there could be very annoying speed instabilities due to internal sector reallocations and some other mysteries with no-so-bad/good sectors and heads. I have seen small LBA interval slow downs even up to just 1 MB/s on one 2 TB drive, and the drive still reported very good SMART values - no reallocations, no errors. -- 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 ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
