By user12611852 on Mar 16, 2007
Solaris 10 introduced a powerful virtualization capability in March of 2005 with Solaris Containers. This allowed hundreds of separate applications to run on a single Solaris kernel while providing security isolation. It has almost zero performance impact and very little storage and memory impact. However, a single kernel has caused concern for some customers who need stronger isolation or various kernel patch releases.
Enter "Logical Domains" for the UltraSparc T1 processor current featured in our T1000/T2000 servers.
Logical domains take advantage of the hypervisor built into the US T1 processor allowing up to 32 separate, complete Solaris kernels to run on a single server.
We have a release candidate for external download from Sun Download
Center. This is an unsupported technology preview of Logical Domains
software, providing early access to those interested in the technology.
A blueprint article (Beginners Guide to LDoms, by Tony Shoumack) was published. It's intended to assist the reader in gaining an understanding of how to easily and effectively deploy Sun's Logical Domains technology. The guide works through step-by-step examples that include the commands to set up, deploy, and manage logical domains and looks at commonly asked questions and advanced techniques.
BigAdmin site: (an external discussion forum will be set up shortly)
How to they compare?
I've created this brief (not all inclusive) comparison of Solaris containers and Logical Domains
|Feature||Solaris 10 Containers ||Logical Domains |
|How Many? ||Thousands per server ||32 per server today, 64 in next generation|
|What platforms?||All||UtraSparc T1 and future Sun4v chips|
|Number of unique Solaris Kernels||1||up to 32|
|Patching||Once for all containers||Each one separately|
|Installations||Once for Solaris 10||Once for each OS image|
|Resource Management||Yes, CPU pools or shares||Yes manual virtual CPU assignment|
|Sub-CPU granularity||Yes, fine granularity via fair share scheduler||Yes, 4 logical domains per T1 core|
|Time to create a new instance||Minutes||Greater than 1 hour|
|Disk space required per instance||100 MB||Gigabytes|
|Other OS support||No||Yes in the future (Linux)|
FAQ: Can I run Solaris Containers withing a logical domain?
Answer: Yes. Think of a logical domain as just another platform.
Why should you care?
Customers wanting to make maximum use of their Sun hardware while meeting specific availability, security or management requirement may want to consider logical domains as an alternative (or in parallel with) Solaris containers.
Logical domains are only one of Sun's many virtualization technologies which include:
- Hardware domains in the E4900, E6900 and E25K class servers
- Solaris containers for both Sparc and X64/X86 platform
- Xen (coming later) for the X64/X86 platform
- VMware running under Solaris 10 on X64/X86 platform
- Resource Management in Solaris 9 and 10 on all platforms