hi Tim, On Thu, Jul 27, 2006 at 07:45:03AM -0700, MOEUR TIM C wrote: > Hello List, > > I'm pursuing an architecture for multiple guests under VM and I'd like > to know if anyone else has done the same, or if this is just an accident > waiting to happen. I invite your thoughts, comments, and witty remarks. > > Here's what I'm considering: I'd like to create multiple VM Linux > guests that each have read access to a set of common minidisks. On > those common minidisks will be what I'm calling the shared Linux file > systems, such as stuff in /sbin, /bin, /boot, /lib. Each VM Linux > guest will also have an exclusive minidisk (WRITE) that will contain the > file systems needed to update and operate (/etc, /proc, /sys, /tmp and > so on). The assumption is that each Linux guest will use the same level > of OS, patches, and add-on programs. > > I have two goals with this idea - > > 1) to limit maintenance procedures. I'd only have to apply patches to > one image and all of the Linux guests would be affected. > 2) conserve DASD. > > I can think of several good reasons not to do this: > > 1) Each Linux guest will probably need to run with the largest > allocation of memory. > 2) I'd likely have to shut down ALL guests in order to apply > maintenance, since updating executables on the fly (from some other > maintenance system) would probably invite abnormal results. > > I haven't experimented or detailed the specifics of what directories are > shared and which are exclusive, but I wanted to first pose the question > to this group to see if this is a good way to invite a system crash > across all of my production Linux servers.
Instaed of using minidisks to share the data you should think about using DCSS Segment in z/VM and the xip2fs of linux. This decreases startup time of binaries and decraeses the memory usage of all linux guests together. DCSS is a shared memory segment for the linux guests. xip2fs is a execute in place filesysten (has the same filesystem layout as ext2, so all tools for ext2 can be used). When an executable is started, it is already in memory (in the DCSS) and it is directy executed. All linux guest use the same DCSS so the code is executed multiple toimes, but only one time in memory. There was a paper on developerworks on how to setup such a scenario. Ihno "Never trust a computer you can lift." -- Ihno Krumreich [EMAIL PROTECTED] SUSE LINUX Products GmbH Projectmanager S390 & zSeries Maxfeldstr. 5 +49-911-74053-439 D-90409 Nürnberg http://www.suse.de ---------------------------------------------------------------------- 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
