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Oracle Solaris Containers and Logical Domains provide alternative and comple-
mentary methods to virtualize Solaris systems, so it is natural to compare them.
Solaris Containers provide ultra-lightweight OS virtualization with excellent
isolation, security, observability, fast deployment, resource granularity, and na-
tive performance. However, because many Containers run on a single Solaris in-
stance, they do not permit multiple kernel patch levels to be used. Solaris
Containers also have a few restrictions, such as the inability to run an NFS
server.
In contrast, Logical Domains are more like “business as usual” for system ad-
ministrators and application planners. They are individually installed, patched,
used, and managed, much like physical servers. Oracle Solaris can be installed in
a domain via a JumpStart or by booting from a DVD device, just like on a physi-
cal server. Like Containers, domains can also be cloned from previously installed
and customized instances. However, unlike Containers, a running domain can be
migrated from one server to another even without rebooting the domain.
Logical Domains are available only on CMT servers, whereas Containers are
available on any platform that supports Solaris. Also, because domains host full
OS instances on dedicated CPUs and RAM, they have a larger resource footprint
than Containers. Many more virtualized instances can be hosted on the same
platform by using Containers than by using domains.
Solaris Containers and Logical Domains are complementary virtualiza-
tion technologies. They can be combined without adding overhead by running
Containers within domains to achieve the highest degree of flexible virtualiza-
tion. Separate OS instances can be configured when different OS kernel lev-
els are required, with each OS instance hosting many lightweight, virtualized
Container environments.
Logical Domains provide low-cost, efficient virtualization on UltraSPARC T1, T2,
and T2 Plus processors. Each domain is a separate, independent virtual machine
with its own OS instance. Hardware resources are dedicated to each domain
through a highly granular and dynamic resource allocation scheme.
Compared to other virtualization technologies, Logical Domains provide an ex-
tremely efficient hypervisor implementation that avoids the overhead inherent in
traditional hypervisors, and avoids the license costs of commercial virtualization
products.
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