The Virtualization Cookbook for SLES 10 SP2 - z/VM - IBM

One rule that can be recommended is to only have as few virtual machines logged on (or
disconnected) as possible to handle the workload being presented. Every virtual machine that
is not required should be logged off where appropriate, as this will mean more memory for the
other virtual servers which remain running.
2.5 Password planning
Good passwords are critical to good security. However, requiring many different passwords
generally leads to people writing them down, which clearly detracts from good security.
Sometimes it is difficult to balance these two extremes.
This book considers different system administration roles:
► The z/VM system administrator
► The Linux system administrator
► The Linux virtual server end users
The z/VM and Linux system administrator may be the same person.
The method of backing up z/VM data onto the Linux cloner means that the Linux
administrator will have access to all z/VM passwords. Therefore, the examples in this book
set all z/VM and Linux system administration passwords to the same value, lnx4vm. If the
z/VM and Linux system administrator roles must be kept separate and the Linux administrator
is not to have access to the z/VM passwords, then a different method of backing up z/VM
data must be chosen.
You may want to define a finer granularity for passwords based on the following system
administration roles:
► The main z/VM system administrator (MAINT)
► The z/VM network administrator (TCPMAINT)
► The z/VM Linux administrator (LNXMAINT, Linux cloner, Linux virtual server user IDs)
► The Linux virtual server end users (with or without access to 3270 sessions, with or
without the root passwords)
The sets of passwords that you define will depend on the roles that your organization will
adopt.
12 The Virtualization Cookbook for RHEL 6