Starting out with VM: Opinions sought

[contink]

I'm currently looking at the plethora of machines that dot my attic/office space and it's dawning on me that running all these different machines is not exactly helping my electricity bill much less a cost effective way of doing things parts wise either so I was hoping for some opinions on moving towards VM.

 

Specifically I'm looking at ways to put together a main server which host different virtual servers (VS's) for these roles:

- Win2k3 : File/print server, testing, backups, exchange

- Ubuntu: Zimbra, Subversion

- Win2k8 : testing, learning environment prepping for the future

 

The primary question I need to ask though is what base OS to start with?.. I'm happy enough to retain my existing 2k3 as the base but I'm wondering if I'm going to hit limitations. Specifically I've noted various points about licensing with vista and the newer MS OS's and virtualisation so I'd rather not start off on the wrong foot there.

 

 

Next up is one of network security...

 

I'm keen to make the Ubuntu server useable over the internet but obviously I want to reduce the potential for security exploits, etc... I'm currently using a smoothwall homebrew for the firewall but I'm unsure as to the security implications re: a VirtualServer setup when putting a physical machine on both the LAN and either the DMZ or in front of the firewall. Any tips there would help... I can always go with a seperate physical machine if needs be but obviously that kinda defeats the purpose of things.

 

 

 

In a nutshell I'm a babe in the woods, complete with blankie when it comes to VM so all/any help is appreciated.

[ruggie_uk]

I'm not an expert in this disctinct area, but like you I am currently looking at ways of reducing hardware.

We have just purchased a new Dual Quad Core HP Proliant server with Intel virtualisation technology built in.

I have downloaded XenSource free version that will allow up to 4 operating systems to be installed.

Now this is going to be an experiment for me over this holiday, but if Xen does what it says, it will host the operating systems without needing windows as a base therefore having a very low footprint and working efficiently.

I'm looking forward to it as it means I can just ad servers as needed. Bit concerned about getting raid to work etc but these things are sent to try us

[tmcd35]

Hi,

 

 

We've just had a Dual-Quad Core (yep 8-core's) 16Gb HP ProLient delivered so we can consolidate our growing number of servers. We managed to get both County and the Senior Management Team to buy into, and release funds for, VMWare ESX Standard.

 

I've also just got back from the 4-day VMWare course.

 

Whilst I'm not suggesting you rush out and buy a 8-core server, I would suggest looking at VMWares free server. You mention Ubuntu Linux in your post, so if you are familiar with Linux then I would recommend you use this as your host OS.

 

The main things to watch for with VM, in order, are Memory, NIC's, Disk Space, and processors.

 

For what your after a could Dual core with a couple of NIC's and plenty of RAM would do fine.

[ajbritton]

We've just had a Dual-Quad Core (yep 8-core's) 16Gb HP ProLient delivered so we can consolidate our growing number of servers.

 

I'd be interested to know what sort of thing you are planning to virtualize. Do you have a disaster recovery plan in plan if the actual box should fail?

[plexer]

I run ubuntu server as the host os on my dual core dell 860 PE virtual machine server.

 

Ben

[Joedetic]

Don't use standard debian. It takes some effort to get it to install and it's not supported (or so i was told). I recommend ubuntu server.

[DMcCoy]

On a VM related theme I finally acheived sucess in getting my ESX blades to power off after a shutdown!

 

Normally they stay on with the words "Power Down" on it, not good if its a thermal shutdown. At last (after 2 years!) I have it powering off. I was patching today and installed the latest OpenManage, I noticed that it *could* power the machine off. I wanted to know why!

 

I finally found out its an option in /etc/sysconfig/ipmi that just needs to be changed from no to yes. I didn't spot it in the past as openmanage didn't support all the ipmi options on ESX.

[Abaddon]

Xen free download page appears to be offline at the moment. Pity - i had some free time to play today.

[dhicks]

> Bit concerned about getting raid to work etc

 

I initially set up four Xen machines at work and a VirtualBox server at home.

 

Xen at work is running on Ubuntu Desktop 7.04, with Xen 3.1 compiled from source (not that tricky, just make sure you install all the package dependancies, and that way you get the open source version and a more up-to-date version than that currently in Ubuntu's reposatory). Each machine has a seperate, fast harddrive for the host OS and a RAID array to hold data and the guest OS images. In the end I had trouble getting a six-disk RAID 5 array working with Xen - the machine needed drivers for the two SATA cards I'd installed, and Xen replaces the default Ubuntu kernal with its own, and recompiling drivers was just too much palavar. Seems to work fine on the other servers, though - we'll see what performance is like when the children come back :-)

 

VirtualBox at home is different - nice GUI, works under both Windows and Linux, no problems with drivers. I use it for test server setups. Still isn't quite a finished product, though. I have the impression that performance is a bit slower than Xen, although the two systems work in different ways (VirtualBox doesn't make use of the hardware virtualisation facilities, it uses its own techniques). I'm going to be upgrading my home desktop machine to a duel-core processor, so we'll see how it runs on that. Should be possible to transfer virtual machine images between the desktop running Windows and the server running Ubuntu.

 

I didn't try for a cluster setup for the Xen machines - seemingly this requires iSCISI devices, which sounds like another layer of processing to slow things down, really. Moving Xen VMs around proves to be a tad more tricky than it first seems - the VMs exist on sparse files created with dd, which is fine, until you try to copy them, at which point they seem to become non-sparse files... So if you have a disk image file that you've set to take up 400GB (because you start with a large file size because Xen doesn't allow you to resize files...), then copy it to clone the machine, you need a lot of disk space.

 

--

David Hicks

[Geoff]

cp should handle sparse files just fine. For other things, you need to abuse tar.

 

tar -Scf - sparse.file | ( cd copy; tar -xf -)

 

Is the same as

 

cp sparse.file copy/

[tmcd35]

 

I'd be interested to know what sort of thing you are planning to virtualize. Do you have a disaster recovery plan in plan if the actual box should fail?

 

Well, the original spec was for 4-cores and 8Gb Ram. Then we were looking very heavily at an MIS (forget it's name) that relied heavily on MS SQL so we beefed up the spec to cope. When we decide to go with E1 nobody thought to reduce the spec again

 

We have around 7 servers which we are consolidating and then spreading their current workloads over multiple virtualised servers.

 

Basically it the usual mix of File servers, Application Servers, Web Servers, Databases and Print Servers.

 

Eventually, towards the end of the consolidation phase next year, the best of our existing servers will be given more RAM and a copy of ESX to balance the load and provide a level of redundancy.

 

We have a 2TB NAS box that the VM's are being backed upto once a term. This will be stored off-site and provide DR if the worst should happen.

[srochford]

We've just had a Dual-Quad Core (yep 8-core's) 16Gb HP ProLient delivered so we can consolidate our growing number of servers.

 

I'd be interested to know what sort of thing you are planning to virtualize. Do you have a disaster recovery plan in plan if the actual box should fail?

 

I don't know what the OP is planning to do but one of the excellent things about a VM is that it's incredibly easy to backup and, if the host fails, you just put the backup onto AN Other machine and off you go.

 

Of course, you want a fairly high spec machine but even a reasonable desktop these days would let you access most of the things you might have on a server (although a bit more slowly)

 

We've been using VMs for learning with for a while (MS Virtual Server centrally and MS Virtual PC in classrooms); we're just about to virtualise some "live" servers so I have my fingers crossed (which does make typing difficult!)

[contink]

Next up is one of network security...

 

I'm keen to make the Ubuntu server useable over the internet but obviously I want to reduce the potential for security exploits, etc... I'm currently using a smoothwall homebrew for the firewall but I'm unsure as to the security implications re: a VirtualServer setup when putting a physical machine on both the LAN and either the DMZ or in front of the firewall. Any tips there would help... I can always go with a seperate physical machine if needs be but obviously that kinda defeats the purpose of things.

 

Thanks for all the comment so far...

 

The bit above is now the big question I'd like answered as obviously I don't want to leave the server wide open to abuse.

 

Having looked around it seems that the server would basically be as secure as the least secure OS, in particular the VMWare and host OS which makes sense and I guess leaves me somewhat wary of putting a vmware server on to the net without trying things out a bit first.

 

If nothing else I'm thinking that two seperate servers is a good plan.. one in the DMZ with the other in the LAN.

[Ric_]

@contink: With some clever virtual network adapters and VLAN configuration you could separate out your DMZ machines.

[contink]

@contink: With some clever virtual network adapters and VLAN configuration you could separate out your DMZ machines.

Unfortunately I have to admit that VLAN is something I need to learn more about and right now I have to limit my book and learning time somewhat.

 

The expression, a little knowledge is a dangerous thing, springs to mind.

 

I'd be interested in what this would involve but right now I figure 2 seperate machines is a good start to get used to VM without leaving my LAN open.

[Ric_]

You could use two separate physical NICs and bind the VMs accordingly... it would be the same thing effectively.

[contink]

You could use two separate physical NICs and bind the VMs accordingly... it would be the same thing effectively.

ok..

 

But how does that effect the host OS? Do the NICs have to be accessible on the host level as well?

 

Right now I'm looking at using my existing Server 2003 as the host OS in the interim but I'm aware that putting multiple NICs on it would create problems with multi-honing.. hence the question above.

[tmcd35]

If you decide to pay out for something like VMWare ESX Starter then the virtualisation software is best thought of as a virtual network infrastructure that with virtual switches that your virtual machines connect to. The virtual switches connect to your physical switches via any physical NIC's on the host server.

 

With this set up you can have a virtual switch that is the DMZ connected with the physical NICs to the out side world. You can then have a second virtual switch with no access to the physical NICs. You can then make a virtual machine as a firewall and connect it to both virtual switches.

 

If you stick with the free VMWare Server product then, AFAIK, the NIC'sare always controlled by the host OS. There is no way of assigning a NIC only to be used by a guest OS. With this product this product the guest OS literally shares access to the NIC's with the host.

[Geoff]

If you stick with the free VMWare Server product then, AFAIK, the NIC'sare always controlled by the host OS. There is no way of assigning a NIC only to be used by a guest OS. With this product this product the guest OS literally shares access to the NIC's with the host.

 

Not so, at least with Linux, you can create per VLAN interfaces (see my HOWTO) and assign each logical vlan interface to a guest.

[ranj]

how is virtualisation with Server 2003 as the host and Gentoo linux as a virtual machine. Anyone had any problems?

 

I am looking to implement at our school. I can decide whether I should use VMware or virtual server 2005. Any ideas would be great.

 

thanks

[ranj]

does anyone know if gentoo linux runs in a virtual machine?

[Geoff]

Yes it will.

[diggory]

Thanks for all the comment so far...

 

The bit above is now the big question I'd like answered as obviously I don't want to leave the server wide open to abuse.

 

Having looked around it seems that the server would basically be as secure as the least secure OS, in particular the VMWare and host OS which makes sense and I guess leaves me somewhat wary of putting a vmware server on to the net without trying things out a bit first.

 

If nothing else I'm thinking that two seperate servers is a good plan.. one in the DMZ with the other in the LAN.

 

One nice thing about VMWare security I suppose is that it's 'footprint' is pretty small - which makes me happier than using say Hyper V.

You can also setup 'virtual' switches on it to seperate you networks (maybe get some more NICS or use VLANS if you have managed switches?).