Hi, 02.08.2007 13:49,, Carsten Ralle wrote:: > Hi, > > I've been struggling with Bacula for a single backup installation for > almost 4 months now. Although installation and configuration are well > documented I'm still confused by two problems we can't get solved: > > 1. Even with brand new tapes, on two different tape drives, using > continuous cleaning cycles, the tapes that used to store between 11.5 > and 13 GB uncompressed data on a windows machine only take about 8 GB > using bacula (same drive, same tapes).
Same set of files? > Following the advice to switch off software compression when hardware > compression is enabled, we run tests with following results (always the > same fileset of 23 GB uncompressed data) > > hw-compress sw-compress spool size data/tape total # of tapes used > on on 14 GB 8.2 GB 1.7 > on off 23 GB 12.9 GB 1.8 > > so we use the installation with both sw and hw compression turned on, as > it gives us better performance and less tapes/backup. > > Why is it impossible to store more then 8 GB on a 12/24GB tape. Again: > we ran the tests on multiple different drives (HP15xx and Sony > DDS3-drives). I think Martin explained this... > 2. Up to now a verify at level "VolumeToCatalog" always (!) brings up at > least one error of the type "Error: block.c:317 Volume data error at > 3:2817! Block checksum mismatch in block=2817 len=64512: calc=8fe728a4 > blk=bd217fe3" in the middle of the tape. That indicates a real problem. Is the error always at the same position (the 3:2817 information) or does the position vary? > After that bacula dupms the whole remaining file list into an email > message of about 30MB in size. > > - Is there any way to make Bacula stop to send the file list while keep > on sending email notifications ? Again, Martin's suggestion sounds good. > - How can it be, that a single error renders the whole tape of a backup > useless ? Why does bacula not continue to verify the other 80% of a > backup and tells something like "block error while reading ..., missing > files ...." ? Difficult question... the basic idea is "if I find a single data error I decide the whole tape is no longer reliable". For backup / restore purposes, that is reasonable IMO. For verifies, you're probably right that a warning and continuation would be better. But you could try to run bls / bscan with the -p option... or even the SD with -p, but be aware that I at least don't know what that might create... Also, a look into the system log might reveal something interesting like lower-level SCSI or tape problems that the driver reports. This sort of problems, naturally, can not be corrected by Bacula, only reported. > > Thanks for any hints, > > Carsten > > > > The installation I'm talking about runs on a 2.0.36 Linux kernel with a Admittedly rather old kernel version, but it should work anyway. > single Sony SCSI DDS3 tape drive (12GB uncompressed) inside a 8-slot > auto-changer (drive and changer are the only devices on the SCSI bus) > The team drive+changer work together as expected. > > We run about ten other backup installations using commercial tools and > Amanda. So far, bacula was the one easiest to set up among the free > tools, but after 4 month of testing we haven't got single backup which > runs through and verifies without an error. If you consider four months of testing easy to set up I don't want to know what a difficult deployment looks like at your site ;-) > I know, that DDS is not the idal choice as we run some SLR, LTO and VXA > solutions, but for that particular case the tape drive has to be DDS3 as > the customer in question has a large library which only handles DDS and > MiniDV tapes. MiniDV as data storage tapes? Which library and drives would that be, if you can share that information? (And, slightly related, wouldn't the customer be better off if he replaced a big DDS library with a smaller LTO one?) Arno -- Arno Lehmann IT-Service Lehmann www.its-lehmann.de ------------------------------------------------------------------------- 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
