I would ask why you don't allocate it all? Say 14G of cstor and 2G of xstor? Are you planning for a 2nd z/VM LPAR?
6GB would likely be very sufficient for z/VM and a single Linux DB2 Conn Server guest. I'll venture that much if it helps :-) And probably without even paging.. What it mostly depends on is the virtual memory size of your guests. As long as you have sufficient paging space - you can overcommit your memory. 2 or 3:1 is likely as far as you want to go unless you're willing to suffer performance degradation. That is - if you have 3 Linux guests using 4G of memory each -- you would be overcommited at a 2:1 (V:R) ratio. It also means that since you are overcommitted by 6GB - you'll want 12GB of paging space (6 3390-3). You want to have twice as much paging space because you want paging to stay at 50% or less. The paging requirements are based on 'worst case', though -- meaning that all 3 guests are using ALL of their memory and are all actively paging. Scott Rohling On Thu, Dec 2, 2010 at 7:45 AM, Dazzo, Matt <[email protected]> wrote: > We are entering the world of zvm/linux with a z10bc-2098 n04 and 16gb total > memory. I am trying to decided what to allocate to zvm/linux as a starting > point. Our initial thoughts and a recommendation from our VAR was 6gb. The > first application will be DB2 Conn Server and not sure what's after that. > I'd like to find out how much memory other shops have allocated and what > applications they support. Is our initial 6gb a decent starting point? I > know the IBM standard answer 'it depends' but I am looking for some clarity > and guide lines. > > Thanks > Matt > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
