The concurrency I'm aware of is at the hdisk/lun level.  There's a 
num_cmd_elems at on the fcs adapter which we set to 2k, and then queue_depth on 
the hdisk.  That's why spreading I/O across as many hdisks/luns as possible is 
advantageous. 

Rick



-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Huebner, Andy
Sent: Wednesday, July 15, 2015 9:33 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Disk layout for AIX

He claims there is a queuing issue with too many at the HBA.  I guess I missed 
that the last 12 years of being a storage/TSM admin.
I told him the theory of using many was to allow more concurrency.  Before we 
build I just want make sure this is not a mistake that cannot be easily fixed.

Thanks,

Andy Huebner

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
David Ehresman
Sent: Wednesday, July 15, 2015 8:12 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] Disk layout for AIX

VGs are cheap.  Why does your AIX admin want to reduce the number of VGs?

David Ehresman

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Huebner, Andy
Sent: Wednesday, July 15, 2015 9:03 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] Disk layout for AIX

I have an AIX admin that wants to build my new TSM server using two VGs for the 
database (6 file systems) and one VG for the various logs.
We currently have 6 VGs for the DB and 3 VGs for the logs.  Each VG contains 1 
file system.

The DB is about 375GB and the new hardware is a P8.

No TSM de-dup.

Should I be concerned about the DB setup?


Andy Huebner


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