A Beginners Guide to LDom Sun Microsystems’ Logical Domains (LDoms) technology “provides the ability to split a single physical system into multiple, independent virtual systems.” (BEGINNERS GUIDE TO LDOMS: UNDERSTANDING AND DEPLOYING LOGICAL DOMAINShttp://www.sun.com/blueprints/0207/820-0832.pdf) In effect, one machine is able to support multiple systems running CPUs, memory, and devices, each independent and secure from one another. Security, scaling, kernel management, patch sets, and packages can be applied to individual systems as required. There are other ways to partition systems, such as Solaris Containers, Solaris Resource Management, Sun Fire Domains and XVM. LDoms are ideal for environments requiring management for multiple kernels, or increased security between servers. However, a huge benefit is the reduction in administrative support as a result of the management of one kernel image. What makes this technology possible is the hypervisor, a software layer between the operating system and hardware. It is the hypervisor’s ability to act on behalf of the OS to manage and control hardware that enables this technology. Ultimately, with this consolidation of resources, data centers are not only more efficient; costs can be significantly reduced. There are four types of domains, the Control Domain, Service Domain, I/O Domain, and Guest Domain. The first domain to be installed is the Control Domain. This is where the Logical Domain Manager resides and is responsible for communications with the hypervisor. The Service Domain shares the virtualized services, such as network switches. The I/O domain controls and shares physical hardware devices when needed. The guest domain is where the virtualized systems are located, and reports to the Control Domain. “The guest domain must run an operating system that understands both the sun4v platform and the virtual devices presented by the hypervisor. Currently, this is the Solaris 10 11/06 OS with required patches 124921-02 and 125043-01 (with kernel update 118833-36) at a minimum.” (BEGINNERS GUIDE TO LDOMS: UNDERSTANDING AND DEPLOYING LOGICAL DOMAINS)
After the analysis of your system resources and desired configuration, you are ready to install and setup LDoms. How you setup and configure your system will depend on your specifications, however, at minimum you will have one Control Domain supporting one Guest Domain.
I will demonstrate the power of mdb(1) by displaying kernel data structures related to virtual memory (VM) in order to show how to dump the contents of any running application's memory or any page of memory in general. As an example I will run a simple shell script that I will end up locating in the shell's heap. When I first figured out this example, it was an educated guess on my part that a shell script would end up in the heap of the shell interpreter. The file name of an interpreter script (files starting with #!) gets passed to the invoked interpreter as one of its arguments.
Recently, a customer asked to review the value proposition of Sun's UltraSPARC T2 servers vs x86 servers. I started off by providing some benchmark results. This page on Sun's web site is a good starting point to access those benchmark results:
Virtualization is the big buzz word these days. I would like to describe one of the older virtualization techniques around: Virtual Memory (VM) on Solaris 10. Every 32-bit application, command, utility (e.g. ls, vi, fmd, acroread, oracle process, etc) is given 2 to the 32 = 4Gb of virtual memory to potentially use. 64-bit applications are given 16 Exabytes of virtual memory which is 4 billion times more than 32-bit programs.
Ijoined Forsythe to be able to work closely with a person whose name kept popping up every time I taught a DTrace class for SunEd. A customer in the class would say oh yea Jarod Jenson was here last week or last month and he solved our performance problem in less than a day. I wrote the DTrace course (SA-327-S10) for Sun Educational Services starting in March of 2004 and then taught it for 3 plus years (as well as Solaris 10 Internals, Multi-threaded Programming and Crash Dump Analysis) before joining Forsythe.
There is only one way to describe dtrace.conf(08) - sick.
The software developer talent present at this conference (at a mere 70 or so folks) has got to be the highest concentration of insanely gifted develepor talent ever assembled. When you have presenters talking about pte's, TLB's. CR3's, VMM's, and traps and the majority of the audience is not only engaged, but experts in the field - you have a conference at the next level.
I am not just talking about MacOS X or FreeBSD here. DTrace works great for Solaris versions prior to Solaris 10 as well. In fact, it works great for Linux and Windows too.
Symantec describes Enterprise Vault as "... software-based intelligent archiving platform that stores, manages, and enables discovery of corporate data from email systems, filer server environments, instant messaging platforms, and content management and collaboration systems.
virtualization.info
