ADSM-L

Re: [ADSM-L] Tape performance (was: Re: Preferred TSM Platform)

2009-03-03 11:34:53
Subject: Re: [ADSM-L] Tape performance (was: Re: Preferred TSM Platform)
From: Wolfgang Moeller <moeller AT GWDG DOT DE>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 3 Mar 2009 17:33:43 +0100
Alex Paschal <apaschal AT MSIINET DOT COM> writes:

>[...]
> Have a look at the 'fcstat' command recently introduced into AIX.  This
> will output an unpleasant bunch of data, but some nice scripting can
> isolate the FC SCSI Traffic Input Bytes and Output Bytes lines for the
> desired HBA, even if the HBA doesn't have disk on it.  A loop, fcstat |
> grep | awk, sleep , and a subtraction will give you bytes/second
> numbers.  Heck, it'll even give you cool stuff like IP over FC bytes if
> you use it.

Cute.

IBM: Please, make the command work on the JS21 (1st generation blades), too!
Currently it's not operational there - surely that's because of the QLOGIC HBAs.

We happened to get a bunch of (4-way) JS21s, and (given fast FC disks) they
make for surprisingly speedy TSM servers, likely because of their CPU 
horsepower.

As regards basic tape I/O statistics: In 'topas', the "Readch/Writech" values
(upper right corner) have always included tape I/O. Served me well enough
in the past ...

- Wolfgang J Moeller @ GWDG

(who had to help IBM adapt the _TSM_device_drivers_ to the QLOGIC HBA :-)