On 2/23/07, James Melin <[EMAIL PROTECTED]> wrote:
Sadly, no. I am not joking. I was told to remove it, so I did. Under protest. Had it working perfectly. I think it's time to re-visit this, however.
Yes, you should. Some VM folks have old thumbs whose rules don't fit current workload.
What we're being directed to do here at the moment is do shared kernel. I'm running a MAXIMUM of 11 images right now. Three of them on the Test VM LPAR. So what is the benefit? I have two 'test' systems on the prod VM. One is my cloning/update server Two prod websphere, one prod DB2 Connect/CVS/Bugzilla/MySQL instance and 2 QA Websphere instances. In that environment I am going to need at least two shared kernel images. Probably three. So that will buy me the memory footprint of maybe five images at maximum.
There are measurable advantages in sharing the kernel when you are short on memory. Think about the paging handshake between Linux and VM that will let Linux run another process while VM is resolving the page fault. But a page fault in the kernel stops the entire virtual machine. With the kernel in NSS those pages are less likely to get paged out. That's also part of the motivation for shared libraries in XIP. It helps to let VM treat one page different from the other. Whether advantages outweigh the cost for your installation depends on many things. Not all pure technical. Rob -- Rob van der Heij Velocity Software, Inc http://velocitysoftware.com/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
