Dwight Cook wrote:

>      In the past even IBM experts were split, I can't say how they feel now
>
>      What we've done is put the DB & LOG files under JFS and made all the
>      diskpool storage raw.

Raw vs JFS is an interesting issue.  Up until now I've gone RAW (on everything)
since it is quicker to setup and is higher performance.  Now however I have been
informed that database corruption can occur if a second server instance is 
started
(no mention of storage pool space but it would appear to be subject to the same
problem).

Furthermore, according to an internal but third party source, AIX RAW device 
code is
not being improved while JFS performance is.
Now I'm leaning toward JFS

>
>
>      ALSO went to great lengths to put the volumes that contain a db or log
>      file as the first disk out a port (SSA) and that the db copies and log
>      copies were on a different card
>

If you only have one SSA initiator the highest activity usage should be at the
mid-point of the loop; presumably this gives the router equally good paths to 
the
data.  With multiple initiators (interface cards) I'd place the highest activity
usage at the mid-points between the two initiators.

> ______________________________ Reply Separator 
> _________________________________
> Subject: ADSM Database as raw device faster?
> Author:  g.rentschler (g.rentschler AT rus.uni-stuttgart DOT de) at unix,mime
> Date:    7/27/98 10:04 AM
>
> Hi,
> we have a RS/6000 as ADSM server. So far I created jfs filesystem for the
> database and created the database volumes as normale files via dsmfmt. As
> far as I know it is possible to use a logical volume as raw device for this
> purpose. What is the recommended way? Is the raw device faster?
> Best regards
> Gerhard
>
> Gerhard Rentschler            email: g.rentschler AT rus.uni-stuttgart DOT de
> Regional Computing Center     tel.   ++49/711/685 5806
> University of Stuttgart       fax:   ++49/711/682357
> Allmandring 30a
> D 70550 Stuttgart
> Germany



--
Steffan Rhoads
Steffan Rhoads
Lead Technical Consultant
Think Enterprise Solutions
10 Holland
Irvine, California  92618-2504
srhoads AT westernmicro DOT com