Virtualization

bobby_valentino · 13 Jul 2008 at 21:29

Hi, just been reading on VMware's ESXi. Iv been messing around installing linux on a VM ware software that I got but the only thing i dont like aobut virtulisation is the fact that software runs on software. Im not sure what hypervisor is, but I think its something along the lines of it allowing the VM ware images to directly communicate with the hardware rather than it being run on software i.e windows. Someone correct me if im wrong, but virtulisation has really lifted of in the server market and it looks the way forward but I just dont get why they'd want to go in that direction espically when dealign with large SAN products etc... if its run on software within software. This would just descrease performance etc...Someone please shed some light on this topic and correct me if im wrong, thanks!

Teledude · 13 Jul 2008 at 22:21

The basics are that vmware is an OS yes but its a very stripped down linux OS

Windows typically doesn't utilise more than 15% of the amount of physical cpu/ram it can - vmware increases pyhsical hardware utilisation to more than 85% thus allowing for a much more efficient use of hardware hence allowing multiple systems to run alongside each other.

A hypervisor is something like ESX that doesnt run on top of another OS (such as MS Virtual Server which runs on 2003)

Vmware compliments large enterprise infrastructures especially when based around a SAN architecture which allows for load balancing, high avalibilty and vmotion - which allows you to move a running "virtual" server from one pyhsical server to another with zero downtime...

oddjob62 · 13 Jul 2008 at 22:24

http://www.vmware.com/overview/why.html

oddjob62 · 13 Jul 2008 at 22:25

Teledude said:
The basics are that vmware is an OS yes but its a very stripped down linux OS

Actually it's just the service console that's Linux based. The VMkernal is not.

oddjob62 · 13 Jul 2008 at 22:39

Teledude said:
vmotion - which allows you to move a running "virtual" server from one pyhsical server to another with zero downtime...

I think Vmotion is one of the coolest things I've ever seen in enterprise IT. We have 2 VMware physical servers in a cluster, currently hosting a dozen VMs. The other day I upgraded the memory on both boxes with no downtime on those hosted VMs