Introducing HP-UX 11i Virtual Partitions

Sep 2007 6
impact on productivity and morale if not done with much careful planning and support. Similarly,
consolidating middleware instances requires a high level of expertise in the middleware, an
understanding of how it is being used by the various business applications, and what performance
impacts may result from the consolidation. Mutually exclusive OS or middleware version
requirements (or both) frequently block consolidation of OS instances. Within a single OS instance,
software may be incompatible. In fact, some Independent Software Vendors (ISVs) only provide
support on dedicated servers.
Hardware consolidation, that is, multiple “virtual” servers on a single physical server, avoids many of
the pitfalls of consolidation at higher levels.
vPars provides a great hardware consolidation solution. It enables multiple virtual partitions, with
unique OS and application requirements and combinations, to share the same physical server.
vPars provides a unique combination of a practical consolidation solution with high-performance,
enterprise-class hardware.
Increased utilization and scalability
Very few data centers achieve utilization rates above 40 percent. This is usually the result of two
common practices: First, there is typically a one-to-one relationship between applications and
servers, which rarely fully utilizes the system. Second, many enterprise-class applications are
resource-intensive, but the high demand is only for short periods. Many businesses have
applications that are cyclic in nature, such as payroll and end-of-month billing. Frequently, the
cycles for the applications do not coincide. Servers are normally configured to handle the peak
loads, causing lower average utilization of the server.
Virtual partitions can be used to improve the ratio of applications to physical resources since:
1) additional virtual partitions (vPar)s can be created to utilize unused resources
2) CPU and memory resources can be moved between vPars when and where required,
without having to reboot the affected partitions
HP-UX 11i Virtual Partitions can dynamically partition hardware and dedicate resources to those
virtual partitions. This provides flexibility in scalability of the individual partitions.
Each virtual partition is allocated: a specified amount of memory, one or more CPUs, and one or
more I/O cards. Hence, multiple, isolated virtual servers, with separate instances of the HP-UX 11i
operating system, applications, and users, run on the same physical server. This is practical for
enterprise-class and mission-critical applications that require the scalability inherent in symmetric
multi-processor servers (SMPs).
Each vPar can scale from a minimal resource vPar to a vPar spanning all the resources on the hard
partition or server. Figure 3 demonstrates how CPUs might be allocated to individual partitions.
Figure 3: vPars – system utilization and scalability
vPar2 vPar3vPar1
textCPU textCPU textCPU text
CPU
text
CPU
text
CPU
vP
ars increase system utilization
,
while pro
v
iding
good partitioning scalability