Hi, On 5/20/2006 3:43 PM, Timo Neuvonen wrote: ...
So, one solution would be using of software compression? I guess Bacula allows it?
Yes, but keep in mind it's done on the client. Your customers or co-workers will hate you if you run your backup jobs with a high compression level during work hours ;-)
Then, the amount of data written to the tape (drive) would be known exactly, and this would propably make it possible to know exactly how much tape there is left. Anyway, for rough estimates one propably could trust the hardware compression to work with almost constant factor too, as long as the environment (including the type of data) remains constant.
In my opinion that's normally the problem... it works for mail files, for log files, and lots of database-related stuff too, but user files tend to be a mixture with a big part of pre-compressed data like media files or OpenOffice.org data, and, at leastthe setups I know, the users tend to create files in a rather unpretictable way :-)
Usually, your approach works best with data created by programs alone or in an environment where yo really know what your users create.
Information on the amount of data written to tape drive is available in the logs, but it's beyond my knowledge how it possibly could be used to automate the recycling decision.
Well, I've done some of it and it's not too difficult, but I guess that once Job Migration is available it will allow later compacting of volume contents.
Actually, it would be nice to be able to define "mark volume full at the end of job if xxx gigabytes has been appended". This could propably be done with an external script, that was called after the finished backup? However, I find calling external scripts to manipulate the database more error-prone compared to built-in features. Am I just too paranoid?
Hmm. Typically I'd say that you can't be too paranoid when dealing with backups. But then, such a script would only modify metadata in the catalog, nothing on the tapes, and it would only mark volumes a "Used", so there should be no risk of data loss.
Finally, I think that the "bac_vol_mgmt.pl" script I posted some time ago can do some of what you want, and could easily be enhanced to allow marking a volume as full if it's "almost" (as defined by any procedure you like; have a look at baculareport.pl) full.
If one tape could normally store eg. 5-6 backups, this actually has little practical value -a constant number of backups before recycling is propably enough, considering the required tolerance. But if a single tape could handle eg. 25-30 backups, this could become more valuable -it might allow eg. one extra month to be available before recycling.
Indeed, but I wouldn't want to keep a tape in a drive for such a long time anyway...
Arno
-- TiN ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
-- IT-Service Lehmann [EMAIL PROTECTED] Arno Lehmann http://www.its-lehmann.de ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
