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Let's run this idea by the group here.

I am thinking about using VMWare Server in production to host

  • a 2008 Domain Controller with DHCP and DNS,
  • a 2008 member server with WSUS, some virus software, and other "management" utilities
  • a second 2008 member server with SQL, IIS, and File Shares for a medium business of 50-100 desktops.

The reason I am leaning toward Server vs ESXi is for backup purposes.

Using ESXi, if I want to backup the VM's, I would need a second server in the office with enough storage availability to hold a copy of the vmdks.

I am wondering if putting this virtual environment on top of a basic 2008 server install will allow for easier backups to both tape and/or to offsite storage using JungleDisk. Can a snapshot be triggered easily via a scheduled job?

I know this doesn't necessarily handle file level restores, but I want to make sure in a DR situation, we can restore production servers quickly.

Does this concept hold water? Would a very minimum install of the 2008 Host remove too many resources from the actual production machines?

This would be a new Dell 410 server with 12 GB ram and (6) 600 GB 15K in a RAID 6, Dual Intel Xeon 2.26GHz procs.

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Running 3 VMs, one of which is a SQL server, on Windows Server 2008 using a 6 disk RAID6 array is probably going to have some bad IO performance. –  ITGuy24 Feb 25 '10 at 19:15
    
Is this IO concern about running these three VM's in VMWare Server on top of Server 2008, or will the IO still be a problem even if it were on ESXi? –  Keith Sirmons Feb 25 '10 at 21:32
    
Reading more on this topic, I now see that snapshotting a VM is good for dev and test, but not production. You can snap a SQL server, but when you restore it, the SQL server still thinks it is at the point in time when the snap was taken. SQL might still think there are clients attached to it and all of those connections would be gone by the time you restore, causing SQL to be "lost" for a while, as well as transactions in process to potentially fail. I believe David Mackintosh is correct for pushing for VSS in your backup solutions. –  Keith Sirmons Mar 1 '10 at 3:03

3 Answers 3

up vote 2 down vote accepted

Don't use VMWare Server in the manner you have described. The problem with 'snapping' a VM in VMware Server is that all you get is a snapshot of the disk at that moment in time. There is absolutely no assurance that the image on the disk is in any way consistent.

Take your SQL server for example. The files on the disk are not necessarily consistent because of actions which may be in the process of being written, stored in memory, or whatever. Taking a snapshot of the VM disk system is no different than pulling the plug on a real server -- the filesystem and applications contained on it may, or may not, survive.

To do it properly you have to

  • signal the apps in the VM to write consistent states to their disk
  • flush the disk buffers to the virtual disk
  • do your snapshot
  • signal the apps in the VM that the snapshot is complete and they can start making changes again
  • do your backup
  • release your snapshot.

There's a reason why backup tools generally cost money. Doing it correctly isn't trivial, and when your company is on the line you are willing to pay money for the possibility of having someone else who is an expert help you in emergency situations. Tools for VMs generally cost even more money, because of the extra investment a VM infrastructure implies.

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Yes, don't backup the VMs, instead backup the business critical data. –  Joe Internet Feb 26 '10 at 4:35

There are a couple tools that allow you to backup a full vm under esxi ( ghettoVCB.sh). You shouldn't need Vmware server to do backups.

A better solution might be to simply split the storage away from the VM server setup your Vmware server to access its storage via NFS. Store your files on a second server or SAN which you will be able to access and backup.

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To do storage and virtualization correctly, you need abstraction.

Keep your x86 server for performing the processing.

Buy a Netapp in order to address the storage requirements for your VMs.

VMserver performance is subpar. You want a type 1 hypervisor for performance reasons.

You'll want to perform some analysis to determine if it will justify moving from a free type 1 to a paid type 1. (e.g. ESXi to ESX).

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