How many vm's

[localzuk]

I have a nice shiney HP DL360 G5 server with dual 2.2Ghz Intel Xeon 5150 dual core processors and 2GB ram.

 

I am using this box as a VMware server with a variety of guest images running. My question is, how many can I throw onto it?

 

I am currently running the school website (5000 hits a week, internal mostly some external) on an ubuntu install (joomla, php, mysql, apache2), RT on another ubuntu install, Jabber (used by the staff only - so max 60 concurrent users) on another ubuntu install, Nagios and Cacti on another one - which only myself and the bursar look at. My question is, can I bung a proxy on one and have that running nicely without issues? Or am I pushing it?

[StewartKnight]

I would think that you're pushing it, but mostly because of the RAM, but by the sounds of things you're not pushing the network traffic yet. I'd keep an eye on processor useage too.

[CyberNerd]

you could run all those services on a single ubuntu install, in which case I'm sure it would cope with squid/dansgardian. whats the load looks like?

[plexer]

What os are you running on the server itself or is it a bare metal esx or whatever it is called install?

 

Ben

[localzuk]

It is running on a Windows 2003 server. Ram wise things are looking fine at the moment (max 50% being used at once), CPU wise, it is never going above 10% utilisation.

 

I don't want to combine all those things on one image as that would defeat the point of using seperate vms. I am going to be combining the RT and nagios images though.

 

That would mean I had 3 vms running. I guess I could try it with a squid vm and see how it goes, if it doesn't like it shift it elsewhere.

[CyberNerd]

It is running on a Windows 2003 server. Ram wise things are looking fine at the moment (max 50% being used at once), CPU wise, it is never going above 10% utilisation.

 

Sounds like it can handle some more stuff, but I'd say bad idea running a windows host. VMWare runs best on Linux for several reasons:

ESX is based on a linux kernel, most of the R+D is focused towards running linux host, the free server edition isn't for production enterprise use - its a port.

Ntfs has poor support for large file sizes, you get better performance on XFS,JFS.

Windows has higher overhead - you can't cut a 2k3 server down as well as a headless no gui linux box.

Linux allows you to control processor memory usage, per VM session and fine tune priorities.

You also need to pay for it, and in this instance it doesn't make sense to - IMO use windows when there isn't a better alternative.

 

 

I don't want to combine all those things on one image as that would defeat the point of using seperate vms. I am going to be combining the RT and nagios images though.

It wouldn't defeat the point, the point of VMWare is so you've got high reliability and can move the server images areound easily if you have a hardware fault or need to run from backup - not so you can cram 100 servers onto one physical box

[NetworkGeezer]

VMWare is Linux? So haven't they read the GPL then?

[CyberNerd]

good point - it's what an IBM/ESX reseller told me last week

[localzuk]

Sounds like it can handle some more stuff, but I'd say bad idea running a windows host. VMWare runs best on Linux for several reasons:

ESX is based on a linux kernel, most of the R+D is focused towards running linux host, the free server edition isn't for production enterprise use - its a port.

Ntfs has poor support for large file sizes, you get better performance on XFS,JFS.

Windows has higher overhead - you can't cut a 2k3 server down as well as a headless no gui linux box.

Linux allows you to control processor memory usage, per VM session and fine tune priorities.

You also need to pay for it, and in this instance it doesn't make sense to - IMO use windows when there isn't a better alternative.

 

I do intend to swap things over when I can, but that will be half term - and it will be a gutted ubuntu server machine.

 

It wouldn't defeat the point, the point of VMWare is so you've got high reliability and can move the server images areound easily if you have a hardware fault or need to run from backup - not so you can cram 100 servers onto one physical box

 

It would, as if all the functions are in one single image, I can't split one off easily if I need to - for example if the jabber service is expanded to allow access for all pupils etc... Also, the idea of vm boxes is so that you can put a bunch on a single machine (not 100, but a handful) - it allows you to use underutilised equipment for multiple tasks in multiple OS's, is it not?

[CyberNerd]

to clarify: wikipedia

 

VMware ESX Server

 

VMware ESX Server uses a stripped-down proprietary kernel (derived from work done on Stanford University's SimOS) that replaces the Linux kernel after hardware initialization. The Service Console (also known as "COS" or as "vmnix") for ESX Server 2.x derives from a modified version of Red Hat Linux 7.2. (The Service Console for ESX Server 3.x derived from a modified version of Red Hat Enterprise Linux 3.) In general, this Service Console acts as a boot-loader for the vmkernel and provides management interfaces (CLI, webpage MUI, Remote Console). This VMware ESX hypervisor virtualization approach provides lower overhead and better control and granularity for allocating resources (cpu time, disk bandwidth, network bandwidth, memory utilization) to virtual machines. It also increases security, thus positioning VMware ESX as an enterprise-grade product.

 

[CyberNerd]

It would, as if all the functions are in one single image, I can't split one off easily if I need to - for example if the jabber service is expanded to allow access for all pupils etc... Also, the idea of vm boxes is so that you can put a bunch on a single machine (not 100, but a handful) - it allows you to use underutilised equipment for multiple tasks in multiple OS's, is it not?

 

I see what you mean, I'd be inclined to rationalise them as much as possible though- for each VM guest you'll be using a certain amount of disk/memory.

I'm running a dual 2.8GhZ RHEL server that has Requesttracker/Nagios and RM KS3 APS server running locally it has 2* windows 2000 servers one of which is a print server and one is a web server (legacy reasons, ideally they'd be on the same image). It runs happily and I reckon it would take another low usage windows server (probably a DC) without problem

[DMcCoy]

It is running on a Windows 2003 server. Ram wise things are looking fine at the moment (max 50% being used at once), CPU wise, it is never going above 10% utilisation.

 

Sounds like it can handle some more stuff, but I'd say bad idea running a windows host. VMWare runs best on Linux for several reasons:

ESX is based on a linux kernel, most of the R+D is focused towards running linux host, the free server edition isn't for production enterprise use - its a port.

Ntfs has poor support for large file sizes, you get better performance on XFS,JFS.

Windows has higher overhead - you can't cut a 2k3 server down as well as a headless no gui linux box.

Linux allows you to control processor memory usage, per VM session and fine tune priorities.

You also need to pay for it, and in this instance it doesn't make sense to - IMO use windows when there isn't a better alternative.

 

 

I don't want to combine all those things on one image as that would defeat the point of using seperate vms. I am going to be combining the RT and nagios images though.

It wouldn't defeat the point, the point of VMWare is so you've got high reliability and can move the server images areound easily if you have a hardware fault or need to run from backup - not so you can cram 100 servers onto one physical box

 

Just a few things. ESX is a custom kernel, the console you use, while based on Red hat, is itself a virtual world within the ESX kernel. There is no real prefererence to linux hosts for vm server. Windows is quite capable of running several VMs too. I'd also suggest that NTFS is just a good for large files, as ESX uses its own filesystem to get around the limitations of linux and windows ones. You can't have folders in vmfs for example. Plus if you use Windows Server 2003 Enterprise as the host os, you are allowed to run 4 Virtual enterprise 2003 servers on it with the same license.

 

Edit. Got to the bottom of the thread too late!

 

I would also say the point of Vmware is consolidation, not reliability.

[Ric_]

It's also worth remembering that VMWare Server allcoates the memory to each VM instance. This means that turning on three servers with 1GB of RAM will use 3GB of RAM on the host OS... despite the fact that each client OS is currently only using 100MB for example.

[DMcCoy]

I'm not sure if vm server includes the baloon memory driver or not, but esx will use a defined % of the allocated or increase as it gets used.

[localzuk]

It's also worth remembering that VMWare Server allcoates the memory to each VM instance. This means that turning on three servers with 1GB of RAM will use 3GB of RAM on the host OS... despite the fact that each client OS is currently only using 100MB for example.

 

Hmm... That isn't true from what I've seen. I have vms with 1GB set for them and they are only using 256MB at the moment according to windows.

 

If that were the case I would seriously doubt the usefulness of virtualisation for consolidation purposes!