Carl,
        I wonder about this comment for two reasons.  First, I have 7133 D40 
drawers which don't appear to be problematic.  But a month or so ago we 
rebuilt a server and found that "Enable Fast-Write Cache" was not set to 
"Yes".  Is it possible that you had a similar problem?  We identified it as a 
problem when the recovery log format took at least 4 times longer than we 
expected.

Secondly, I'm in the process of doing some performance tuning on another 
system with this hardware, and find no real problems with Raid 5 on this dasd 
type.  How did you notice that AIX was waiting for the drawer?  The "monitor" 
program?

What kind of performance is the Shark advertised as doing?  What do you 
actually see with this hardware?


-Matt
>Across the network.  We were looking at IO stats trying to find the
>Across the network.  We were looking at IO stats trying to find the
>bottleneck as 20 hours for 40Gb was woefull, even for NT, and we found the
>server was waiting for the D40 drawer.  We moved the backup pools across
>to the shark and it's dramatically faster.
>
>We're now seeing that CPU/network performance is the limiting factor.  The
>slowest clients are a couple of P200Pro NT servers, the fastest some H80s.
>All across 100BaseT.


/**
 **    Matt Bacchi                   mbacchi AT us.ibm DOT com
 **    IBM Global Services                SDC Northeast
 **    F6TG; MD Filesystems/Internet     (802) 769-4072
 **    ADSM & AFS/DFS Backup             (tie) 446-4072
 **/