This is AMAZING!

  This will *break* my business case requirements.  I have two
environments each with two libraries, one virtual and one physical, with
7 storage nodes each, some on DDS.
 


David L. King


-----Original Message-----
From: EMC NetWorker discussion [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On
Behalf Of Howard Martin
Sent: Tuesday, November 28, 2006 5:12 AM
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Subject: [I] Re: [Networker] Question on drive target sessions?

If EMC has done this then they are in my opinion unfit to "design" 
software - I know that in the past people have asked for an optional
hard limit on sessions per drive, so they have more control, this
'feature' 
makes it impossible to control networker in ways that we rely on. 
ie. setting target sessions to one for a large server then when it is
happily sending a partition to each of several tape drives setting the
sessions for the other drives up to 4 so slow backups will interleave
and keep the drive humming - it's not perfect but it reduces the backup
time for one server from ~12 hours to 4 hours!
I would have to avoid any version on Networker as brain dead as this!

On Mon, 27 Nov 2006 12:49:14 -0500, Landwehr, Jerome
<jlandweh AT HARRIS DOT COM>
wrote:

>This is something I too have seen at version 7.3.2
>
>After months of having a case open, this is the (infuriating) response 
>I
finally got:
>
>
>Here is the details of the target sessions behavior and how it is
expected to work in NetWorker 7.3.x. Hope this explains the changes in
target sessions behavior comparing to the previous version of NetWorker
and related concern from Jerry.
>
>Background:    Prior to the changes made to target sessions behavior,
we 
had many complains from different customers about one or few devices are
being hammered when other devices sitting idle doing nothing
(eligible/enabled devices). This was only an issue when we had different
target sessions settings for each device, and say the first device had
it set to 10 and others set to 1 or 2. in this scenario by getting 8
save sessions coming to the networker storage node the first device
(selected as per device selection criteria) was hosting them all 8
sessions and remaining devices sitting idle.
>
>Due to couple of enhancement request to address above issue for better
utilization of the eligible devices, a fix has been implemented to query
the respective storage node and it's eligible devices, then select the ?
lowest? target session setting amongst the devices and use this number
as the target session value for all devices for the backup in order for
better distribution and load balancing on incoming save sessions.
>
>Suggestions    While attempting to utilize more devices (if possible)
is 
a good thing, I would ask Jerry however to make the target sessions
value more close to minimize the request for additional volumes and
slightly improve the performance. Values from 1 to 10 as per above
explanation could have negative impact on resource utilization and as
per above explanation and in this configuration value 10 not taking
effect eventually because of the lowest number. So either setting the
target session value in a range like 4-6 is recommended (if it is really
required to be different) or making some changes to the configuration
(group,
client?.etc) to achieve better resource allocation also performance.
>
>As we have mentioned the Escalation LGTpa89210 is open on device 
>request
issue and the fix is not verified yet. This escalation is however is a
side effect of other settings especially target sessions and with making
suggested changes this will not be a problem.
>
>
>
>So rather than telling customers to fix the target sessions to their 
liking, they 'fixed' the software to find and use the lowest target 
sessions available on any device for the storage node and ignore the
user 
setting!
>
>this broke my environment since I have two jukeboxes connected to the 
storage nodes: a VTL jukebox with target sessions set to 1 for all 
devices, while the LTOII jukebox has significantly more target sessions
on 
each of it's devices
>
>the result is that whenever a LTOII savegroup kicks off, I get a
hundred 
messages emailed about all the storage nodes wanting more tapes than
they 
need...  nice!
>
>Jerry

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