Re: SAP save with parallel drives

[DrFranken <midrange@xxxxxxxxxxxx>]

Obviously there are other things to consider but if it takes 18 hours to 
write to LTO4 then they have more than a couple hundred GB of data *OR* 
a fantastically bad DASD subsystem!

Assuming the prior (despite the lack of evidence) then saving to dual 
drives is with near certainty going to help. Best cast of course would 
be 9 hours but more likely 'about 12' would be my estimate and possibly 
as low as 10 best case. Some things like SAVSYS need to go to just one 
tape and that will then include security which if badly done I've seen 
take 5+ hours all on its own. Thus from the end of security best case is 
remaining time in half and work up from there.

Given they are fiber you don't have the possibility of a 5901 card not 
being able to drive two drives flat out, even a 5774 can push two LTO4s 
to the limit so now you're down to disk I/O and sufficient memory. If 
they run SAP they probably have plenty of both! LOL!

        - Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 8/29/2019 11:05 AM, Jim Oberholtzer wrote:
> One of my customers runs SAP on POWER.
>
>   
>
> We will be doing an OS upgrade on one of those partitions,(not replicated)
> and we found out the save process to a single LTO4 fibre tape was 18 hours.
> Ouch.
>
>   
>
> We have tape library with multiple drive sleds in it, so my question is;  In
> a SAP environment does doing saves to parallel tape devices help or hurt the
> performance of the save?
>
>   
>
> --
>
> Jim Oberholtzer
>
> Agile Technology Architects
>
>