Networker

Re: [Networker] Question on target sessions?

2006-07-20 17:51:47
Subject: Re: [Networker] Question on target sessions?
From: Darren Dunham <ddunham AT TAOS DOT COM>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Thu, 20 Jul 2006 14:50:17 -0700
> Why is it that if the total number of save sets for a group exceeds the
> value of the drive target sessions (in our case 4), and you only have
> one writable tape, NetWorker will wait until the first 4 save sets have
> completed before sending the next pending ones to tape?
> 
> NetWorker does ask for a second writable tape, and yes, if I had one
> available, it would mount it, and then it would be writing 4 save sets
> to drive 1 and 4 to drive 2, but I don't understand why it can't start
> sending save sets that were previously pending to drive 1 as soon as one
> of the running save sets completes. Instead, it seems to want to wait
> until all 4 are complete, it then pauses for a minute and then continues
> with the next 4, and so on. Is this normal behavior? It would be nice if
>  it could send stuff there as soon as something frees up and not wait.

That seems unusual to me.  I can't say that I've seen that behavior.
However, I don't think it's a setup that I've seen very often

I don't know if you can do this, but it might be interesting to find if
it does the same thing when you only have one drive available.  Rather
than having an 'up' drive with no media, can you have just one drive
enabled?

(of course since target sessions is not a hard limit, you may see many
more than 4 streams going to the drive rather than a nice run at 4 while
streams start and stop).

When backups are limited by global or client parallelism figures, you do
see the behavior that you are talking about.  New streams begin as soon
as one stops.

-- 
Darren Dunham                                           ddunham AT taos DOT com
Senior Technical Consultant         TAOS            http://www.taos.com/
Got some Dr Pepper?                           San Francisco, CA bay area
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