On Thu, Sep 27, 2001 at 07:57:48AM -0500, Lundy, Mark wrote:
I think 4 tape drives per mediaserver is too much.
It's depends on tape drives you are using. 2 DLT7000 tape
drives should be able to saturate 100 Mb/s pipe.
There is no such thing as round robin for stus for NetBackups 3.4
It's strict alphabetiacal order.
Hopefully in 4.5 it will be something else. I heard a lot of guys testing it.
> We seem to have run into a storage unit limit. We have 4 robots (32, 32, 16
> and 16 drives in each) and 10 media servers. A Veritas consultant
> recommended that we define storage units in a round-robin manner with 4
> drives each so that the load gets spread out over the media servers and
> robots as much as possible.
> So, 96 drives divided by 4 equals 24 4-drive possible stus for our entire
> robots. 24 4-drive stus times 10 media servers equals 240 storage units
> total. The stu definition looks something like this:
>
> mediaserverArobot1 (4 drives)
> mediaserverBrobot2 (4 drives)
> mediaserverCrobot3 (4 drives)
> mediaserverDrobot4 (4 drives)
> mediaserverErobot1 (4 drives)
> mediaserverFrobot2 (4 drives)
> mediaserverGrobot3 (4 drives)
> mediaserverHrobot4 (4 drives)
> mediaserverIrobot1 (4 drives)
> mediaserverJrobot2 (4 drives)
> mediaserverArobot3 (4 drives)
> mediaserverBrobot4 (4 drives)
> mediaserverCrobot1 (4 drives)
>
> and so on until all 240 are defined. This Veritas consultant informed us
> that stus are picked in alphabetical order, Thus, when a backup stream is
> started, as 4 drives become busy, another stus is chosen for any more jobs
> and the load is spread out over not only the media servers, but over the
> robots as well.
> The problem with this config is, according to Veritas, every backup job has
> to traverse the stus list and confirm its ability to communicate with each
> stu As you can imagine we have a large environment and over 3000 backup
> jobs run nightly. 3000 * 240 = way too many for our E4500 master server to
> deal with and all jobs expire with 196 errors.
> Now, finally to my question, what is the most stus any of you have defined?
> I backed my config down to 40 stus, with each stu defined with the number of
> drives in the library and it is working just fine. However, that doesn't
> accomplish the load balancing that I desire. I.e, media server one will
> handle all backup requests until robot one busies all of its 32 drives
> before the any jobs go to media server 2 and/or robot two. TIA.
>
> Mark
>
>
> -
> Mark W. Lundy
>
> I.T. Recovery Management
> Work: 816.965.1131
> FAX: 816.965.1042
> <mailto:mlundy02 AT sprintspectrum DOT com> mlundy02 AT sprintspectrum DOT
> com
>
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Andrew Shinkarev
Network Systems Specialist
Abbott Laboratories
(847) 9387559
shinkara AT pprd.abbott DOT com
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