IBM ZVM - FOR LINUX V6 RELEASE 1, Getting Started

Page: 42 / 172

1.
Determine a set of applications that will run in a Linux virtual server. The set
might include one or more applications that process a given workload. For
example, if you use a WebSphere application, you need to include the
WebSphere application server and the JVM.
2.
Determine the total memory requirement for the application set.
3.
Add the memory requirement for the Linux operating system to the
application set memory requirement. Enter the result in the left column in
Table 2.
4.
If you plan to run the same application set in more than one Linux virtual
server (for instance, you want to have replicated virtual servers to distribute
the workload), multiply the result from step 3 times the number of replicated
servers. Enter the result in the right column in Table 2.
5.
Repeat steps 1 through 4 for each application set.
6.
Add up all the figures in the right column of Table 2, including the memory
requirement for z/VM, to get a total.
7.
Calculate the central and expanded storage sizes.
8.
Record the number of real CPUs available, which helps you determine how
many virtual CPUs each virtual machine has.
Table 2. Memory requirements worksheet
Application set plus Linux
x Number of virtual
servers x Memory estimate
(MB)
1
2
3
4
5
z/VM: 40
Total:
Central storage estimate (Total x .75):
Expanded storage estimate (Total x .25):
Number of real CPUs:
You are done estimating. Later, you will measure your system’s performance and
fine tune the configuration.
Guidelines for estimating the amount of DASD you need
Here are some guidelines on estimating the amount of DASD you need.
For z/VM paging
v
Provide sufficient paging DASD for the paging subsystem. As shipped, z/VM
has one full paging volume, which might be sufficient for your system. A rule of
thumb is to provide twice as much DASD space as your total virtual storage
28
z/VM: Getting Started with Linux on System z