Re: i hosting i question

[DrFranken <midrange@xxxxxxxxxxxx>]

Holger,

	I believe it was the 8/9 thing they fixed with the large cache cards. 
If you recall VIO now requires disks formatted to 528 byte sector to do 
RAID which is now sufficiently large to contain the full sector from IBM i.

	Now if I had a link to the correct documentation, however I have slept 
often since then!!

        - Larry "DrFranken" Bolhuis

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

On 11/27/2017 9:27 AM, Holger Scherer wrote:
> IIRC correctly, there was some statement in the IBM Performance manuals about "I on i is 5% faster than i on VIOS" - but i need to review in the current performance handbook if this is still valid. Using internal disks with VIOS and RAID Cards is not recommended at all as VIOS does no proper write caching; additionally you'll see the 8/9 sector overlap creating more I/O. Using internal SSD this might not be that issue, but with HDD we read enough about problems here in this forum.
>
> If redundancy is not that issue, i on i for a small amount (<20) of LPARs is ok (given the hosting i LPAR has enough RAM). For availability, a dual VIOS is highly recommended - and do not run a VIOS as single instance, as VIOS sometimes locks their config DB and one needs to restart the VIOS :-/
>
> -h
>
>
> > Am 27.11.2017 um 15:04 schrieb DrFranken <midrange@xxxxxxxxxxxx>:
> >
> > We had multiple customers do the same, strip VIO and replace with IBM i for internal hosting and for the same primary reason but other reasons as well.
> >
> > Do be aware that this performance issue was very true 'some time ago' but had been corrected. The actual issue was the way that VIO handled RAID sets on large cache cards such as the FC #5913 and friends. The problem caused excessive I/O from VIO to disk (double if I recall correctly) and you can readily see that being a performance issue. Eventually IBM released fixes for VIO to correct that.
> >
> > That said I need to see a pretty definitive reason for VIO over IBM i for hosting on internal disk