Re: [Bacula-users] multiple concurrent tape jobs

[Heitor F. <he...@ba...>]

>> I am working with an LTO-4 tape library. It has two drives but I plan to write
>> to only one for backups.

>> I will backup to disk first, on another SD. Later, I will copy the jobs to the
>> tape library on this new SD
>> which is on another server. The copy jobs will be spooled to local SSD before
>> being written to tape.

>> re http://bacula-users.narkive.com/QRkTVfEz/typical-tape-write-performance

>> Now what I'm thinking of is streaming multiple concurrent jobs to a single
>> drive.

> Did you test if it is possible? (I can test for you in a dummy environment if
> you want). I don't remember if it is or if the bellow quote only applies to
> copy jobs...

> "If the Migration control job finds a number of JobIds to migrate (e.g. it is
> asked to migrate one or more Volumes), it will start one new migration backup
> job for each JobId found on the specified Volumes. Please note that Migration
> doesn't scale too well since Migrations are done on a Job by Job basis. This if
> you select a very large volume or a number of volumes for migration, you may
> have a large number of Jobs that start. Because each job must read the same
> Volume, they will run consecutively (not simultaneously)."
> (http://www.bacula.org/5.2.x-manuals/en/main/main/Migration_Copy.html)

Nevermind, Dan. Since version 7.0 I think it is possible multiplexing copy jobs and you will be just fine: 

"Migration/Copy/VirtualFull Performance Enhancements 
The Bacula Storage daemon now permits multiple jobs to simultaneously read the same disk Volume, which gives substantial performance enhancements when running Migration, Copy, or VirtualFull jobs that read disk Volumes. Our testing shows that when running multiple simultaneous jobs, the jobs can finish up to ten times faster with this version of Bacula. This is built-in to the Storage daemon, so it happens automatically and transparently." 

Regards, 
-- 
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Heitor Medrado de Faria - LPIC-III | ITIL-F | Bacula Systems Certified Administrator II 
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