* Wolfram Schlich <[email protected]> [2010-05-14 17:54]: > * Ulrich Leodolter <[email protected]> [2010-05-14 13:09]: > > 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. > > [...] > > > 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).
Dear Kern, dear Bacula developers, do you plan to change this part of the implementation of Bacula to greatly improve the speed of copy jobs for tape-to-tape copies? Thanks. -- Regards, Wolfram Schlich <[email protected]> Gentoo Linux * http://dev.gentoo.org/~wschlich/ ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
