* Ulrich Leodolter <[email protected]> [2010-05-14 13:09]: > Hi,
Hi Ulrich! > On Fri, 2010-05-14 at 10:27 +0200, Wolfram Schlich wrote: > > Hi! > > > > I'm using Bacula 5.0.2 to back up to a tape library > > which has two LTO-4 FC tape drives. Backup speed is > > around 95-100 MB/s which is quite ok (using a DAS > > for spooling data though). > > > > Now, when running a copy job that copies backups > > from a tape from the full or incr backup pool to > > a tape from the offsite pool, speed reaches 50MB/s > > maximum, so it's just half as fast as the backups. > > > > What could be the reason for that? > > > > copy is NOT done in multi-threaded buffered way. > it is done one by one block (default is 63k) > > ... > read block N > write block N > read block N+1 > write block N+1 > ... > > so you get about the half speed. What the ... ?! :( > this is why we do a second copy-disk-to-tape > using a special sql query to make offsite copies. Well, the problem for us is that we don't backup to disk because the storage isn't big enough for that, so we backup to tape using the storage as spool device (which is able to spool data for 4 LTO4 tapes). Guess we're lost then. Happy happy, joy joy *sigh* Thanks for the hint! Regards, Wolfram ------------------------------------------------------------------------------ _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
