From: Kern S. <ke...@si...> - 2008-07-30 19:50:50
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Hello, I can see that having separate machines driving different drives within a single autochanger could significantly improve speed, but Bacula already has significant difficulties dealing with multiple drives on a single machine, so this situation is far more complex in terms of communications an locking. At the moment, I don't really see how to implement this, and in any case with the current equipment it is impossible because I don't have such an autochanger. If you can find a programmer to design and implement this, I would be willing to discuss it with him/her to determine if it is feasible. I hesitate to add this to the projects list until we find someone who can design and implement it. Certainly in another couple of years this and the project about writing a single job to multiple drives at the same time will be very interesting projects, but I suspect that at the moment, unless someone can come up with some serious programming resources, these are a bit high end for Bacula (at the moment), especially since there are a number of really critical functionalities that are missing. Best regards, Kern On Thursday 17 July 2008 18:05:54 Shad L. Lords wrote: > Item 1: Allow tape drives to be associated with autochanger > resource on different host > Origin: Shad Lords <slords at lordsfam dot net> > Date: 17 July 2008 > Status: > > What: Allow tape drives that are part of an autochanger but are > connected to different hosts to be associated with the robot > autochanger. > > Why: Many large autochangers that have multiple drives recommend > connecting drives up to different hosts to improve library > performance. Doing so allows you to utilize full bus > bandwidth, split pool space, and utilize separate cpus to > achieve maximum throughput. > > Note: A single robot controls multiple drives but is only connected > to one machine. It is currently possible to work around > things by having remote hosts issue mtx commands over ssh but > nothing prevents multiple mtx commands from being issued at > the same time. > > Note: By not being able to associate drives with their autochanger > you may not be taking full advantage of available drives for > backup/restore purposes. In a job you can't specify multiple > libraries/drives, however all the drives on both (multiple) > hosts have access to all tapes in the library and there isn't > any reason any one of the drives couldn't be used for > backup/restore purposes. > > Note: Sample config: > > host1-sd.conf > ============= > > Autochanger { > Name = ait4-changer > Device = ait4-drive1 > Device = ait4-drive2 > Device = ait4-drive3 > Device = ait4-drive4 > Changer Command = "/usr/lib/bacula/mtx-changer ..." > Changer Device = /dev/sg0 > } > > Device { > Name = ait4-drive1 > Archive Device = /dev/nst0 > Drive Index = 0 > Auto Changer = yes > Media Type = ait4 > ... > } > > Device { > Name = ait4-drive2 > Archive Device = /dev/nst1 > Drive Index = 1 > Auto Changer = yes > Media Type = ait4 > ... > } > > host2-sd.conf > ============= > > Device { > Name = ait4-drive3 > Archive Device = /dev/nst0 > Drive Index = 2 > Auto Changer = yes > Media Type = ait4 > ... > } > > Device { > Name = ait4-drive4 > Archive Device = /dev/nst1 > Drive Index = 3 > Auto Changer = yes > Media Type = ait4 > ... > } > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge Build the coolest Linux based applications with Moblin SDK & win > great prizes Grand prize is a trip for two to an Open Source event anywhere > in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Bacula-devel mailing list > Bac...@li... > https://lists.sourceforge.net/lists/listinfo/bacula-devel |