Zitat von Stephen Thompson <step...@seismo.berkeley.edu>: > On 09/25/2012 10:43 AM, Alan Brown wrote: >> On 25/09/12 17:43, Stephen Thompson wrote: >>> Our Sun/Oracle service engineer claims that our drives do not require >>> cleaning tapes. Does that sound legit? >> >> In general: true (as in, "Don't do it as a scheduled item"), but all LTO >> drives require cleaning tapes from time to time and sometimes benefit >> from loading one even if the "clean" light isn't on. It primarily >> depends on the cleanliness of the room where the drive is. >> >>> Our throughput is pretty reasonable for our hardware -- we do use disk >>> staging and get something like 60Mb/s to tape. >> >> 60Mb/s is _slow_ for LTO3. You need to take a serious look at what >> you're using as stage disk and consider using a raid0 array of SSDs in >> order to keep up. > > > Why do you say that's slow when the max speed appears to be 80? > > http://en.wikipedia.org/wiki/Linear_Tape-Open >
The maximum *native* speed with uncompressed data is 80Mb/s. As the drives do compression to get more data to the tape the speed to deliver data must be higher. If you use the optimistic 2:1 compression from marketing your tape drive is actually crawling with 30Mb/s which is not even 50% of the native speed. If you suspekt bacula bug you can still use dd to fill the tape and see what you get in speed/capacity. 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