Networker

Re: [Networker] daily networker contention...

2012-02-28 13:34:17
Subject: Re: [Networker] daily networker contention...
From: Francis Swasey <Frank.Swasey AT UVM DOT EDU>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Tue, 28 Feb 2012 13:33:58 -0500
I have not forgotten that simultaneous clones/stages and recoveries are not 
possible today from
the same AFTD.

However, I do not see that task 1 issuing a clone for saveset A from AFTD0 to 
POOL0, task 2
issuing a clone for saveset B from AFTD1 to POOL0, and task 3 issuing a stage 
from AFTD1 to
POOL1 must wind up with task 1 running, task 2 holding AFTD1 and waiting for a 
tape in POOL0 to
be available, and task3 holding a tape in POOL1 waiting for AFTD1 to be 
available.

Nope, it doesn't have to be that way.  If all of those tasks acquired their 
source (AFTD0/1)
and THEN acquired their target (a tape in POOL0/1) - task 1 and 2 would run, 
then task 3 would
run.  No problem.   As it is right now, task 1 runs, and task 2 & 3 deadlock 
each other until
task 1 completes.  Then task2 and task3 fight it out over who gets to read from 
AFTD1 and they
run in succession.  While task1 is running, both AFTDs  and both tape drives 
are held hostage.

Frank


On 2/28/12 1:13 PM, bingo wrote:
> As long as 2 different initiators try to control the environment at the same 
> time using different destination pools this is the obvious result. My 
> suggestion: Let the DB admins run their backups but take control over cloning 
> and staging to avoid such problems in the future.
>
> I would also use the argument that you would be faster able to serve a 
> recover request. Do not forget that simultaneous clones/stages and recoveries 
> are not possible today.
>

-- 
Frank Swasey                    | http://www.uvm.edu/~fcs
Sr Systems Administrator        | Always remember: You are UNIQUE,
University of Vermont           |    just like everyone else.
  "I am not young enough to know everything." - Oscar Wilde (1854-1900)

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