Installing flash on CentOS

   Simple solution:

http://www.yqed.com/install-flash-player-10-centos-64-bits/

1. Start by installing those libraries (.i386 and .x86_64):
# yum install curl compat-libstdc++-33 glibc nspluginwrapper
2. Once done with the kitchen work, it is time to install the Flash Player RPM.
# rpm -ivh /tmp/flash-plugin-10.0.12.36-release.i386.rpm
3. Close all Firefox windows and open a new one. In the address bar, type:
about:plugins

 There you go.  Thats it.  Have fun playing kitten cannon.

Starting "Screen Sharing" vnc connection from the command line (Mac OS X)

   Big shout out to Bob237 for the answer to this question.

   I wanted to make it easy to start a vnc session with the new Xen machines I had created.  However, I was having a problem that when I invoked:

open vnc://1.2.3.4:5901 

and entered my password the Screen Sharing window would go white.

   Apparently if you want to start a Screen Sharing session from the command line (Mac OS X) you must first open 'Finder' and browse to /Applications (or /System/Library/CoreServices), right click on Screen Sharing.app and check the box that says "Open in 32-bit mode".

   That's it.  The next time you run the the open vnc command you should have no problems.

Link:
http://discussions.apple.com/thread.jspa?threadID=2414203&tstart=135

Xen: Unable to allocate memory

   So it was rather frustrating that after I got all of the domUs created and ready when I rebooted the machine it decided to not start 3 doms.  After talking with a colleague I was directed to the following page:

http://wiki.xensource.com/xenwiki/XenBestPractices

   In the above link it says to modify '/boot/grub/menu.lst' and add the following:

dom0_mem=512M loglvl=all guest_loglvl=all

   then you are to edit '/etc/xen/xend-config.sxp' and modify/add the follwoing:

(dom0-min-mem 512)
(enable-dom0-ballooning no)

   After setting these options you need to restart the machine and all of the domUs (5+) should start without any errors of "allocating memory"