Monday March 03, 2008
As I was saying
As I was saying[Read More]Posted by jsavit [Sun] ( March 03, 2008 06:39 PM ) Permalink | Comments[0]
Thursday March 01, 2007
Once again, "Mainframe Linux vs. Unix"
Not my title, but the title of a web article touting mainframe Linux. There may be articles showing that mainframe Linux is a good thing, but this is not one of them. Read more to see why it doesn't present a lucid argument for mainframe Linux, and what the consumer should know.[Read More]Posted by jsavit [Sun] ( March 01, 2007 02:41 PM ) Permalink | Comments[25]
Monday February 26, 2007
Response to: IBM, Sun and HP: Comparing UNIX Virtualization Offerings
Ken Milberg, a technical editor for IBM Systems Magazine, Open Systems edition, wrote an article comparing and contrasting virtualization technologies from IBM, Sun, and HP. You might not expect an impartial analysis from an IBM publication, but you might hope. Unfortunately, he got a lot of things wrong, both about Sun technology and IBM's. I'll go over some of the mistakes and misleading comments.[Read More]Posted by jsavit [Sun] ( February 26, 2007 11:12 PM ) Permalink | Comments[5]
Friday February 02, 2007
Two questions, 1.5 answers...
Two questions (and a partial answer) about when LDoms will be available and whether it requires spending money. I can answer part of that![Read More]Posted by jsavit [Sun] ( February 02, 2007 04:08 PM ) Permalink | Comments[0]
Saturday January 27, 2007
And now for something virtually different...
The previous entries describe some of the complex, slow and tricky things needed to implement virtual machines the "traditional" way. This entry gives an overview of how Logical Domains work, and align with CMT architecture, and why they are a completely different approach for low-overhead virtualization.[Read More]Posted by jsavit [Sun] ( January 27, 2007 10:10 AM ) Permalink | Comments[3]
Sunday December 24, 2006
Trickiest (virtual) bits - more on why virtual machines are hard to do well
Some parts of making virtual machines work are especially tricky. Read here for discussion of several of the most difficult aspects of virtualization, and how they are handled on different architectures.[Read More]Posted by jsavit [Sun] ( December 24, 2006 03:37 PM ) Permalink | Comments[0]
Tuesday December 05, 2006
Why virtual machines are hard
In my entry "Virtual history", I mentioned that some aspects of virtual machines were hard to do efficiently, and then hand-waved over the details. I'd like to spend a few minutes (it's late...) mentioning just a few of the things to be considered. Let's delve into that some now.[Read More]Posted by jsavit [Sun] ( December 05, 2006 09:06 PM ) Permalink | Comments[0]
Thursday November 16, 2006
A slight digression with Logical Domains and Apache
Before I carry on describing architectures for virtual machines and other forms of virtualization, a related anecdote driving Apache web server under logical domains (LDoms)[Read More]Posted by jsavit [Sun] ( November 16, 2006 07:51 PM ) Permalink | Comments[0]
Saturday November 11, 2006
Virtual history
A little historical perspective on different forms of virtualization, leading (eventually) to constrast with Logical Domains and Solaris Containers (zones)[Read More]Posted by jsavit [Sun] ( November 11, 2006 08:44 PM ) Permalink | Comments[2]
Thursday October 26, 2006
It's a virtual world out there
I've finally been tempted to start posting blog entries. Yet Another Form Of Electronically Mediated Communication, but a good one. Most of my posts, at least, the computer-related ones, will be related to server virtualization. It's interesting times now, as a formerly niche technology has become mainstream. As somebody who happily lived for a long time in that niche (mostly in the context of mainframe VM) it's interesting to see a large number of people discover how useful virtualization can be, along with some of the pitfalls you can run into. In a world where there a virtual machines or partitioning technologies on almost every platform (VMware, Xen, Solaris Containers, LDoms, xPars, Virtual Iron and others), you can see people rediscovering issues like nested memory managers (hint: LRU no longer works the way you think). virtual timer management, and other aspects virtualized environments.Posted by jsavit [Sun] ( October 26, 2006 01:17 PM ) Permalink | Comments[0]