vCenter Server 4.0 - What OS do you prefer?

[evolmar]

Hello all,

Thanks to all of your help I have one ESX host hooked up to our EMC Clariion and am running VMs off of a 525GB LUN. I wouldn't be able to get this far without your guidance. It's much appreciated.

My first VM is VirtualCenter. After spending a good portion of the day messing around with ODBS drivers (yay!) I finally have it up in and running in Windows Server 2008 64-bit. For the first half hour or so after it has been up the memory overusage alarm has been tripping. This VM has 4GB of RAM dedicated to it. It's been an hour as of this writing and it seems to have calmed down. It's hovering at around 2.5GB of usage right now.

Did I do the wrong thing by using Windows Server 2008? Would the memory usage be lower if I just went with Windows Server 2003 instead? The VC database is on a separate server. Would it just be a simple matter of just building a new VM, installing VC, and pointing to the database to maintain all of my vCenter settings?

Once again thank you all for your help.

Regards,

e

[davidbarclay · Accepted solution]

It's easy to stick with what works (i.e. Windows 2003 R2 x32)...but now it's supported on Windows 2008 x64..we are looking to standardise on it. I've also read somewhere that "32bit support may be removed in future versions" but I can't remember where I saw that. May as well get it sorted now IMHO.

As for ODBC issues, yes..you need to look at the this KB article.

Dave

[DLeid]

Hi evolmar,

Need a little more info:

How much memory is installed on the host?

What is the roll of the Windows 2008 guest? App Server, Domain Controller, SQL Server etc.

Depending on the role a server plays is how I would determine how much memory to give a vm.

You say it's your first vm, so I assume no other vms are on the ESX server. So if your getting memory alarms thats strange (for me) for just one vm on a box.

When vms initially start up they go thru a red, yellow and then a green state until stable and this is normal. But if your getting alarms ( I'm going to assume its Virtual Center giving you those alarms) you should check how much memory the host has as well as the guest. Check also if there is any swapping going on.

I would also prefer to use the latest OS, so that would be Server 2008 and I would work with it until it works.

[davidbarclay]

I think the question was specifically about a vCenter VM...not VMs in general.

It's worth mentioning that roles like AD controller are not supported on a vCenter server.

Dave

[DLeid]

My bad

I should have read more carefully.

[AsherN]

I loaded mine on a 2003 server w/ 1GB. Saw the same thing. The VM consumed 90% of available RAM. I would surmise that vCentre simply grabs as much memory as it can. Could very well be a case of that's one VM where you ignore memory alarms because you will never be able to satisfy it.

[malaysiavm]

here is my experience to share, some problem are created by the tomcat, you may want to disable it if you do not need the features, or you need to fine tune the memory consumption on the tomcat too.

Beside that, I found that the respond from win2k3 is much more better versus win2k8. Microsoft just slow down the server performance on windows 2008.

Craig

vExpert 2009

Malaysia VMware Communities - http://www.malaysiavm.com

[evolmar]

Hi evolmar,

Need a little more info:

How much memory is installed on the host?

What is the roll of the Windows 2008 guest? App Server, Domain Controller, SQL Server etc.

Depending on the role a server plays is how I would determine how much memory to give a vm.

You say it's your first vm, so I assume no other vms are on the ESX server. So if your getting memory alarms thats strange (for me) for just one vm on a box.

When vms initially start up they go thru a red, yellow and then a green state until stable and this is normal. But if your getting alarms ( I'm going to assume its Virtual Center giving you those alarms) you should check how much memory the host has as well as the guest. Check also if there is any swapping going on.

I would also prefer to use the latest OS, so that would be Server 2008 and I would work with it until it works.

Hi DLeid,

We have 32GB on the host. It is a Dell Poweredge R710.

I was just talking about the vCenter VM. I assigned 4GB to it. I did see what you were talking about. After a while it went from red to yellow and then to green. It has stayed green throughout the day. In the resource and allocation tab I see the 4GB listed under Guest Memory and 3.56 is active. However when I look in Task Manager I see 1.9GB free. I'm a bit confused as to which field I should be monitoring. Other than that everything has been running smooth.

In your experience how much RAM would you allocate to a Windows 2008 guest serving the role of a domain controller? We have about 120 employees here.

The biggest servers we will be virtualizing are file servers and a Blackberry Enterprise Server. We have a few license servers that we plan on virutalizing too. I think I will use Windows 2003 for those.

Thanks for your reponse.

Regards,

e

[malaysiavm]

for the memory tab, you may see host memory utilization and guest memory utilization. At the same time, you may notice the active memory use in your VM from task manager show different. My experience, I think this is normal for both linux and windows as the operating system will manage the memory on the virtual machine, swap or paging file in and out depend on the server activity going on. shouldn't be too much concern about it

Craig

vExpert 2009

Malaysia VMware Communities -

[DLeid]

It all depends.

We have 17 regional offices vitalized out of 21. Each office has a physical server for Exchange and an ESX server hosting Windows 2003 servers domain controller, file server, print server, application server, document foldering server for our document management system ( which is an XP host), an SQL server and a file server. The SQL and File server are used for the document management system. The offices vary in size with two offices with over 300 users and the other offices varying between 40 and 120 users.

Our ESX servers all have 12 GB Ram and six guests. Average host memory usage is about 8GB. The guests are configure with 1GB ram (although I think they can be lower, but we have the memory and management doesn't quite get how ESX handles the memory so it's a trade off.) On average the guests use much less memory than assigned.

See attached screenshots:

You can always start your vm at around 768MB and work your way down or up depending on your user load.

When you look at the task manager of a vm it is showing the utilization of the memory presented to it. The host memory info is different than the guest memory info. I would pay attention to the host memory info and the guest memory info but remember the guest info is about the portion of host memory allocated to it. ( Thats even confusing to me, if you need more clarity let me know.) The best way to see the relationship is to install vmware server 2.0 on a windows host and open the task manager on both. Adjust the memory on the guest and observe the differences in the task managers.

AsherN

I loaded mine on a 2003 server w/ 1GB. Saw the same thing. The VM consumed 90% of available RAM. I would surmise that vCentre simply grabs as much memory as it can. Could very well be a case of that's one VM where you ignore memory alarms because you will never be able to satisfy it.

Virtual Center 2.5 needs at least 2GB RAM with physical or virtual server being used. vSphere's vCenter needs 3GB. So you should give your vc vms the appropriate amount required.

[evolmar]

Thanks again for the replies guys.

This morning, getting fed up with the constant yellow and red I shut down the VirtualCenter VM and bumped the RAM to 4.5GB. Sure enough as soon as I booted it back up the amount of active memory usage plummeted to 2.5-2.7GB. Haha.....can't wwin I tell ya.

It's all good really. I think I'll just leave it as is in case it spikes again.

I really wish they didn't use Tomcat. Or at least give us a VC virtual appliance.

Thanks again for your help guys.

Regards,

e