On Saturday 25 November 2006 15:45, Peter Crighton wrote: > On Sat, 25 Nov 2006 13:00:00 +0100, you wrote: > > >On Saturday 25 November 2006 12:13, Peter Crighton wrote: > > >> I tried tar cvf /dev/nst0 file, with a 32MB file and the tape drive > >> ran continuously for 40s, which is about 800kb/s. > > > >Read the tape back with dd, which should allow you to determine the block size > >that tar used. In fact, if you do an strace on tar, you will see *exactly* > >what it is doing, and you can simply duplicate it in Bacula. It is possible, > >but I will be very surprised if it is writing in 512 byte chunks. > > > > OK, with the command dd of=/home/root/test/tape count=1 </dev/nst0 I > end up with a file called tape of size 512, so I believe that tar is > writing 512 byte blocks, but doing so continuously rather than > repeatedly stopping. > > Out of interest and despite not having completed the fill test in > btape, I have initiated a backup using bconsole. 35MB were backed up > in approx 8 minutes, equating to the 70kb/s that I see with btape (and > confirming to me that the tape is accessed in a bursty fashion within > bacula as I expected). The size is confirmed by using scanblocks in > btape. > > Unless anyone can suggest an alternative setup for my existing tape > drive, I guess now that my options are to accept the performance of > this tape drive, use an alternative backup program, or buy a new (well > second hand off Ebay) drive. > > What are the best alternative type of drive (it's for a home office so > only requires a modest capability). Looking on Ebay DDS-3/DDS-4 drives > and tapes are available at a reasonable cost, giving a comparable > capacity to my current drive and probably almost a no-cost swap if I > sell my existing drive and tapes on Ebay.
I would strongly recommend against DDS-3. DDS-4 is OK, barely so. You will be much better off with a DLT-8000, which is probably more expensive, but if your data is important, it is worth it, if for no other reason than any DDS technology or older DLTs are likely to cause you problems as they have about a 90% chance of failing at some point, either the drives or the tapes. > -- > > Peter Crighton > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Bacula-users mailing list > Bacula-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-users > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
