Sunday, May 18, 2008

WPAR and LPAR comparison

IBM has taken a leadership role in innovation, over the past fourteen years and
has been number one in the patent technology race. Out of this has come a
plethora of new and innovative products. In 2001 IBM announced the LPAR
feature on IBM eServer pSeries and then in 2004 Advanced Power Virtualization
provided the micropartitioning feature. In 2007, IBM announces WPAR Mobility.
WPARs are not a replacement to LPARs. These two technologies are both key
components of IBM's virtualization strategy. The two technologies are
complementary, and can be used together to extend their individual values.
Providing both LPAR and WPAR technology offers a broad range of virtualization
choices to meet the ever changing needs in the IT world. Table 2-2 compares
and contrasts the benefits of the two technologies.
Table 2-2 Comparing WPAR and LPAR
Workload Partitions Logical Partitions
WPARs share OS images LPARs execute OS images
Finer-grained resource management,
per-workload
Resource management per LPAR
Capacity on demand
Security isolation Stronger security isolation
Easily shared files and applications Supports multiple OSes, Tunable to
applications
Lower administrative costs:
1 OS to manage
Easy create/destroy/configure
Integrated management tools
OS Fault isolation
Chapter 2. Understanding and Planning for WPARs 37
Draft Document for Review August 6, 2007 12:52 pm 7431CH_TECHPLANNING.fm
Figure 2-7 shows how LPAR and WPARs can be combined within the same
physical server, which also hosts the WPAR Manager and NFS server required to
support partition mobility.
Important: When considering the information in Table 2-2 you should keep in
mind the following guidelines:
In general, when compared to WPARs, LPARs will provide a greater
amount of flexibility in supporting your system virtualization strategies.
Once you have designed an optimal LPAR resourcing strategy, then within
that strategy you design your WPAR strategy to further optimize your
overall system virtualization strategy in support of AIX6 applications. See
Figure 2-7 for an example of this strategy, where multiple LPARs are
defined to support different OS and application hosting requirements, while
a subset of those LPARs running AIX6 are setup specifically to provide a
global environment for hosting WPARs.
Because LPAR provisioning is hardware/firmware based you should
consider LPARs as a more secure starting point for meeting system
isolation requirements than WPARs.
7431CH_TECHPLANNING.fm Draft Document for Review August 6, 2007 12:52 pm
38 Workload Partitions in IBM AIX Version 6.1

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