John J. McLaughlin: Logical Domains (LDoms) 1.0.1

With the release on LDoms 1.0.1, I expect that many more Sun customers will experiment with this technology and feel confident enough with it to put it into productions.

Honglin Su writes:

Logical Domains (http://www.sun.com/ldoms) is Sun's server virtualization and partitioning technology, and a key element of Sun xVM Infrastructure on Sun servers with CoolThreads technology. LDoms software leverages the hypervisor to subdivide supported platforms' resources (CPUs, memory, I/O, and storage) by creating partitions called logical or virtual domains. Each logical domain can run an independent operating system. Specialized control domain allow the management of these resources using the Logical Domains Manager.

He identifies 5 key new features/benefits

With LDoms 1.0.1, any domains, whether it's a guest domain or a primary domain, are independent virtual machines and they can be configured, started or stopped independently without requiring a power-cycle of machine.
UltraSPARC T2 platforms support (32 domains support at initial release, 64 domains support following)
The Logical Domains MIB (management information base) is delivered as an extension module to the System Management Agent of Solaris 10 running in the control domain. The LDoms MIB helps enable third party system management applications to perform remote monitoring and starting and stopping logical domains using the Simple Network Management Protocol (SNMP).
Domain minimization support - Minimal/reduced Solaris installation for higher security and ease of maintenance
LDoms Browser User Interface (web console, unsupported freeware)

Let's take a look at the release notes and see what's required:

Sun UltraSPARC T1-based servers such at the T1000 and T2000 servers

system firmware: 6.5.x plus patches
Solaris for primary domain: Solaris 10 11/06 OS plus patches
Solaris for guest domain: Solaris 10 11/06 OS plus patches

Sun UltraSPARC T2-based servers, such as the T5120 and T5220 servers

system firmware: 7.0.x plus patches
Solaris for primary domain: Solaris 10 8/07 OS
Solaris for guest domain: Solaris 10 11/06 OS plus patches

The complete list of supported systems:

Sun Fire or SPARC Enterprise T1000 and T2000 Servers
Netra T2000 Server
Netra CP3060 Blade
Sun Blade T6300 Server Module
Sun SPARC Enterprise T5120 and T5220 Servers

Sun recommends 512 Mb for Solaris 10 11/06 OS and 128 Mb is minimum size. The default size for a swap area is 512 megabyte. Note that you should expect to use at least 12 Mb per domain because:

The OpenBoot™ PROM has a minimum size restriction for a domain. Currently, that restriction is 12 megabyte. If you have a domain less than that size, the Logical Domains Manager will automatically boost the size of the domain to 12 megabytes.

The release notes have the specific patch numbers for the Solaris and Firmware patches.

Software That Can Be Used With the Logical Domains Manager:

SunVTS™ 6.3 and 6.4
Sun™ Management Center 3.6 Version 6 Add-On Software
Sun Management Center 3.6 Version 7 Add-on Software
adds support for the Sun SPARC Enterprise T5120 and T5220 servers and contains bug fixes
Sun™ Explorer 5.7 Data Collector can be used with the Logical Domains
Manager 1.0.1
Solaris™ Cluster software can be used only on an I/O domain, because it works only with the physical hardware, not the virtualized hardware.

The system controller software interacts with the Logical Domains 1.0.1 software:

Sun Integrated Lights Out Manager (ILOM) 2.0 (UltraSPARC T2-based servers)
Advanced Lights Out Manager (ALOM) Chip Multithreading (CMT) Version 1.3 (on UltraSPARC T1-based servers)

Currently, you cannot use an DVD to install a guest domain. A guest domain can access the DVD to install applications.

There are many pages in the release notes that detail specific issues and, if available, the appropriate workaround.

Eric Sharakan warns there are two important caveats when upgrading from LDoms 1.0 to LDoms 1.0.1:

Configurations saved to the service processor under 1.0 are not usable under 1.0.1. The LDoms 1.0.1 Administration Guide describes the upgrade procedure that needs to be applied to work around this. Part of this procedure needs to be carried out BEFORE performing the actual upgrade!
You must upgrade both the firmware and LDom Manager components at the same time

Documentation