Fw: Multiple Residency & Shared Memory

["Vasyl Shulzhenko" <vasilis@softline.kiev.ua>]

----- Original Message -----
From: Art S. Kagel <kagel@bloomberg.net>
Newsgroups: comp.databases.informix
To: <tslusser@bigfoot.com>
Sent: 30 ЛЮЪ 2000 Ц. 22:45
Subject: Re: Multiple Residency & Shared Memory


> tslusser@bigfoot.com wrote:
> >
> > Hi,
> > I want to initiate a second instance of Informix OnLine server 7.23.UC1
> > on Solaris 2.6.  My question is "Do I need to set a different shared
> > memory base address or can both instances use the same shared memory
> > segments?"  How would I calculate the shared memory base address for
> > the second instance if it is necessary?
>
> No, the shared memory base address is just the address at which the
engine's
> executables will attach shared memory when they attach to it.  It is an
> internal address and is platform dependent.  Leave that value the same in
> both ONCONFIG files.  The value that has to differ for each instance is
the
> SERVERNUM parameter in the ONCONFIG file.  It is added to a base key
number
> to generate a unique, per instance, shared memory key.  The base key is
> 0x52564800 to which is added 0x10000 * SERVERNUM plus the segment number
> (ie the first or RESIDENT segment for SERVERNUM=1 will have a key of
> 0x52574801 while the first VIRTUAL segment for SERVERNUM=16 will have a
key
> of 0x52664802, etc.).  Just translate the key column in the onstat -g seg
> report to hex to see this effect.
>
> Art S. Kagel