If this one really holds - simple is beautiful is my vote too Steen
Onsdag 22 november 2006 20:32 skrev David Boyes: > > I did not always do that, but I learned that the flexibility of pools > > across different storage devices and media types is less valuable than > > a > > > simple setup. > > Multi-type pools also make backup and storage management policy almost > impossible to implement. If we define a pool as an administrative group > of volumes with a certain set of behavior characteristics (eg, similar > media type, physical location, capability (size of volume, etc), > handling characteristics, etc) it's a lot clearer what's happening. > Wildly different media types and characteristics in the same entity are > both confusing and almost impossible to schedule. > > There's also the operator characteristics. If this were z/OS or some > other operating system with a common media mount capability, then it > wouldn't be a big deal, but the current approach really makes it hard, > esp for wildly different media types. > > Pre-migration, the mixed pools made sense in that you could copy data > from volume to volume by specifying the right options and you did all > the footwork of keeping track of the devices manually. Now, > post-migration, that's bad behavior. Bacula should be in control of > device selection and usage regardless of what data is involved, and to > do that, the selection process needs to be clear in terms of what > volume, with what capability do we need to select, and where should it > be processed. If pools are clear that "this volume in Pool X is > associated with this SD" then the rest of the selection parts fall into > line pretty quickly. > > The side effect is that if you are sharing drives with other > applications (this means when you change magazines, etc too, > Arno...8-)), then you have to start taking the drive offline to Bacula > before you snitch it for some other purpose. This is a bit more > discipline that some shops have at the moment, but it also results in a > much more predictable behavior. > > > The only exception, in my opinion, would be to define the storage on > > the > > > command line - that should alwys have the highest priority. It would > > allow to create pools across different storage devices, but in case of > > serious problems or during emergency restores this might be helpful. > > I'd even go further and argue that the only place that this makes sense > is in a restore when the entire bacula infrastructure has been destroyed > (eg in brestore). Normal Bacula shouldn't permit specifying devices; > that's a big part of the value of the Bacula engine -- it manages all > that stuff. > > The key item for that would be to provide the ability to disable a > device (in case it's broken, has a stuck tape, etc) and take it out of > the device selection process w/o removing it from the configuration > file. > > > Finally, it's not a fault to allow users to shoot themselves in the > > leg > > > - as long as there are enough warnings :-) > > See above. The only place where this makes sense IMHO is in the case of > total destruction of the Bacula infrastructure. At that point, you don't > have any choice but to permit it (and in fact, you have to require it to > get the necessary info to do the restores). > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share > your opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Bacula-users mailing list > Bacula-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-users ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
