Alan Brown schrieb: > On Wed, 31 Oct 2007, Ralf Gross wrote: > > >> I have pretty big full backup (3,2TB) for which I need around 12 LTO-2 > >> tapes > >> (with hw compression on). I use spooling with max size of 215GB, and > >> typically spooling (of max size) lasts 2h50min, while despooling lasts > >> 2h40min. Is this normal that spooling lasts longer than actual writing to > >> the tapes? > >> > >> I would drop the spooling part, but I'm worried about tape shoe-shining. > >> (If only bacula can do despooling and start spooling the next chunk of the > >> same job at the same time.) > > > > Yes, even a simple FIFO with couple of GB or less would be > > sufficient to avoid shoe-shining. Bacula's spooling has other > > advantages than only avoid shoe-shining, but in our case it's not the > > perfect solution. > > have you benchmarked your spool partition with 1 (and more) simultaneous > operations going on?
I did some tiobenchmarks, but I'm not spooling more than one job at the same time. The RAID is capable of ~140 MB/s (seq. writes). But spooling is not my problem (I didn't get you point regarding shoe-shining). Spooling will always cost extra time, thus I'd like to avoid spooling at at all for jobs that take days to finish. On the other hand I would like to avoid shoe-shining, but I can't say for sure if it happens at all during direct backup over net. I only see that bacula writes to tape with 75 MB/s (no spooling) and 77 MB/s with spooling, but not if the drive has to stop 10, 20 or 100 times during this backup. Even the iostat stats of the /dev/st0 tape device are not clear. With or without spooling they sometimes drop below 40 MB/s. Ralf ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
