Hi Andrew

The original reasoning on AIX was that as the data is transferred to
tape AIX gets a spin lock on each 4k page and then has to release it,
so that a system using tape heavily spends quite a lot of CPU
acquiring and releasing locks.

Later versions of AIX have two larger page sizes available and so the
number of locks to be taken and released drops dramatically for the
typical 256KB tape transfer.

I'm not sure whether this reasoning applies to Linux.  If it does then
a larger page size might be beneficial there.

Regards

Steve

Steven Harris
TSM Admin
Canberra Australia.

On 12/03/2015 3:20 AM, Andrew Galloway wrote:
> We have 2 TSM 6.3.5 servers running on zLinux.  Is this something
> we could leverage?
> 
> 
> 
> 
> 
> __________________________ Andrew Galloway Operational Systems
> Continuity Analyst SSC RCMP Technology Directorate CIO Building
> C1035 R.C.M.P. Headquarters 1200 Vanier Parkway Ottawa ON K1A 0R2 
> 613.998.7707 
> andrew.galloway AT ssc-spc DOT gc.ca__________________________
>>>> "Rhodes, Richard L." <rrhodes AT FIRSTENERGYCORP DOT COM> 2015-03-11
>>>> 7:15 AM >>>
> I've been in meetings/training this week about AIX LPM and other
> stuff related with LPARS.  We got talking about our TSM servers,
> and the IBM leader mentioned a presentation given a while ago at a
> IBM conference about using LARGE PAGES (16MB) with TSM to prevent
> lock contention.  This is supposed to help if you drive some large
> number of tape drives concurrently. He mentioned one company that
> implemented this and saw a 20% increase in tape throughput.
> 
> http://www-01.ibm.com/support/docview.wss?uid=swg21649823&aid=1
> 
> I'm curious if anyone out there has heard of this and possibly
> implemented large pages for TSM.
> 
> Thanks!
> 
> Rick
> 
> 
> 
> 
> 
> 
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