A virtual machine (VM) is a completely isolated guest operating system installation within a normal host operating system. It is a software implementation of a machine (i.e. a computer) that executes programs like a physical machine.

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Creating a virtual machine in VirtualBox from a physical one

Is there any way to create a virtual machine that you can use in VirtualBox from a physical installation that you have? For instance, if I have Windows XP installed on a physical computer and want to ...
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4answers
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What range of MAC addresses can I safely use for my virtual machines?

I want to assign my virtual machines MAC addresses so that I can configure DHCP reservations for them so that they always get the same IP address regardless of which host hypervisor they are running ...
24
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4answers
696 views

Will virtualizing a server mean another OS layer to patch and update, more work and greater risk?

I've done a search and have not found anything addressing issues regarding patching and system updates. I've got guidelines that say servers need to have necessary patches. If I have a VM host then ...
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17answers
2k views

Virtualization Pitfalls/Lessons Learned

What are some pitfalls or lessons learned after converting existing hardware to a virtualized environment? Is there anything you tried to virtualize but will never do again?
18
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5answers
1k views

Is there a way to have a virtual machine only have one core yet use three cores on the host machine? [duplicate]

Possible Duplicate: Can a single Virtual Core on a VM use more then 1 physical core? I'm a co-owner of a Minecraft server that is getting rather large each day, but as we get bigger we're ...
17
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10answers
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Running 100 virtual machines on a single VMWare host server

I've been using VMWare for many years, running dozens of production servers with very few issues. But I never tried hosting more than 20 VMs on a single physical host. Here is the idea: A stripped ...
17
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5answers
638 views

Is there a reason to give a VM a round base-2 amount (2048MB, 4096MB, etc) of memory?

The title pretty much says it all, is there any advantage to giving a VM 2048MB of memory instead of rounding to base-10 and doing 2000MB?
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12answers
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Is it possible to setup a virtual machine inside another virtual machine

I have been playing with virtual machines latley, and wondered if I could run a virtual machine inside a virtual machine? Is it possible? Is it practical?
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8answers
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Sync LVM snapshots to backup server

I have a number of Xen virtual machines running on a number of Linux servers. These VMs store their disk images in Linux LVM volumes with device names along the lines of /dev/xenVG/SERVER001OS and so ...
13
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5answers
2k views

Defrag in Windows VM?

I've read conflicting advice on this issue so thought I'd ask here. Should I be running a scheduled defrag within my VM?
13
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3answers
5k views

How is memory allocated in ESXi server?

We have an ESXi 4.1 server with 48 GB RAM. For each VM, we are allocating 4GB of memory. Since the server will have 13 virtual machines, my manager thinks this is wrong. I am going to explain to ...
12
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11answers
31k views

How do I know if I'm working on a Virtual Machine or not?

Is there a way to know if the Windows machine I'm working on is virtual or physical? (I'm connecting with RDP to the machine. If it's a virtual machine it is working and handled by VMWare).
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8answers
784 views

What is this server doing?

I have a bunch of linux virtual servers left over from a previous IT department. They have names like 'magic' or 'stuff'. I'm not quite sure what they're doing...or if I need them... How would you ...
11
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5answers
1k views

Renting a dedicated, but getting a VPS. How to detect? [duplicate]

When renting a dedicated server, how can one be certain than he/she is not getting a VPS or some other virtual machine variant instead of a true dedicated hardware box? Which checks can be run ...
11
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5answers
2k views

So really, what is the overhead of virtualization and when should I be concerned?

I'm searching for good rules of thumb to understand when NOT to virtualize a machine. For example, I know that a fully CPU-bound process with near 100% utilization is probably not a good idea to ...
11
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6answers
28k views

Can I run 64-bit VM guests on a 32-bit host?

Can I run 64-bit VM guests on a 32-bit host? If I have a physical PC with 32 bit can I launch a VM that is 64 bit? What virtual machine software (Virtual PC or VirtualBox or other) would allow this? ...
11
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3answers
5k views

Why VM snapshots are affecting performance?

I read in one of the VMware KB article says that snapshots will directly proportional to VM performance. But my team keep asking me how snapshots can affect performance. I would like to give them ...
10
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3answers
322 views

Application “not supported” in a VM?

We bought some software from a small'ish company, it's a Windows 32-bit video content workflow manager, there's been some customisation by them. We've been working fine for over a year running this ...
9
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11answers
4k views

Any way to run Linux as a Virtual Machine on top of Windows so can have best of both worlds?

Since Linux has a lot of useful tools, while Windows has a lot of apps (like Chrome), instead of buying another machine to run Linux, is there a way to run it as a Virtual Machine on the PC? The ...
9
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4answers
1k views

Can a virtual machine (VM) “hack” another VM running on the same physical machine?

Questions: if a VM is corrupted (hacked), what do I risk on others VMs running on the same physical machine? What kind of security issues is there between VMs running on the same physical host? Is ...
9
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1answer
10k views

KVM and Libvirt - How do I hotplug a new virtio disk?

I am trying to hot-add a file-based disk to a running KVM virtual server. I've created a new disk from scratch using the command dd of=/home/cloud/vps_59/test.img bs=1 seek=5G count=0 and I was ...
9
votes
6answers
35k views

mount.nfs: access denied by server while mounting

On my Ubuntu system, I have this line in /etc/fstab: myserver:/home/me /mnt/me nfs rsize=8192,wsize=8192,timeo=14,intr When I do sudo mount -a I get: mount.nfs: access denied by server while ...
9
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4answers
6k views

Backing up qcow2 kvm guests

I can't find any good info on backing up qcow2 kvm guests. I'm not really interested in the guests running state, only the file system. This question suggests using savevm but that creates a snapshot ...
9
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2answers
1k views

understanding relationship between Qemu and KVM

What is the difference between KVM and Qemu? As I understand, latter is able to provide "user mode emulation" which means that one can run a single executable built for some other architecture like ...
9
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3answers
3k views

EC2 VM import: VirtualBox

I would like to know if it's currently possible to import a virtualbox vm on the ec2 cloud, I have tried with a virtualbox vmdk but it did not succed. Apparently it is designed for VMware's vmdk ...
9
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3answers
9k views

Why can't I ssh into (or even ping) my Ubuntu VM from the Mac OS X host?

I'm running Ubuntu 8.04 as a virtual machine using VMware Fusion 3.0 on Mac OS X 10.5.8. I want to be able to ssh into my VM from the Mac OS X host (so I can use MacFUSE and SSHFS to mount the VM's ...
9
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6answers
18k views

Ubuntu inside VirtualBox is slow [closed]

I am running an Ubuntu instance on VirtualBox inside XP. Here are the details: Host: Windows XP Pro Guest: Ubuntu 8.10 Total RAM: 3GB RAM For VM: 1GB Total Video Memory: 128MB Video Memory for VM: ...
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4answers
5k views

How do I get /dev/random to work on an Ubuntu virtual machine?

Apparently, /dev/random is based on hardware interrupts or similar unpredictable aspects of physical hardware. Since virtual machines don't have physical hardware, running cat /dev/random within a ...
8
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5answers
16k views

Can a Windows 7 Ultimate product key be used for virtual machines as well? [duplicate]

Possible Duplicate: Can you help me with my software licensing question? I have Windows 7 Ultimate running on my computer, and I thought I would set up a few virtual machines to help me ...
8
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2answers
2k views

Vagrant shared folder and file change events

I have ubuntu virtual machine that I'm accessing through Vagrant. On my host (Mac OSX), there is a folder with couple of files, that I share to virtual machine. In that virtual machine, I want to use ...
8
votes
2answers
19k views

Having Mac OS X on a XEN virtual machine

Is it possible to have Mac OS X guest on a XEN host? If yes, how? There are difference for Mac OS X Server? In particular I'm interested in the installation of a testing Mac OS X Server inside a ...
7
votes
13answers
6k views

Suggestion for a simple LDAP server and client

Trying to set up a headless LDAP server on a linux virtual machine (vmware). Small scope, but needs to be reliable and easy to use. Strong preference for simplicity over features, command-line over ...
7
votes
4answers
829 views

Hardware vs software license keys in a VM environment

I am working with a vendor who is supplying a server-based application which requires licensing for activation. There are two options, software-based licensing and hardware (USB-dongle) based ...
7
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5answers
9k views

Portable Virtual Machine Recommendation?

I want to set-up a virtual machine on a pen drive, but I don't know what VM software might be portable or if it's possible to run virtual machine software without installation. Just for starters, it ...
7
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6answers
3k views

Best way to “virtualize” existing system?

I have a fully patched, pristine Windows XP box and would like to create virtual machines that have the exact same setup, OS and software - just differ in disk size, available RAM. The virtual ...
7
votes
2answers
1k views

Virtualbox VM (spawned by Vagrant) running, but inaccessible. What now?

I have a Virtualbox VM running Ubuntu that was started by Vagrant, on an OSX host. At some point, my ssh session to the guest stopped responding. I tried vagrant halt from a terminal window on the ...
7
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1answer
2k views

How to prevent IP spoofing using MAC and ebtables?

I am trying to create IP-MAC pairing rules in ebtables. There are few tutorials and related questions [1] available but I have kind of specific setting. ENVIRONMENT: I have many physical hosts. Each ...
7
votes
3answers
2k views

Entropy on virtual machines

As you might know that it's not as easy to generate entropy on a virtual machine as on a "normal" pc. Generating a gpg-key on a virtual machine can take a while, even with the correct tools. There ...
7
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3answers
2k views

Backing up VirtualBox VMs

Does anyone have a good complete strategy for backing up a bunch of virtual machines running under VirtualBox? I intend to run a handful of virtual machines on a single hardware platform and back ...
6
votes
4answers
2k views

Is it possible or advisable to virtualize a PBX system? How would one go about this?

I'm totally new to the world of VoIP and we are looking to move from our current provider to a solution we host ourselves, mainly because the current service is so unreliable. Unfortunately I know ...
6
votes
10answers
971 views

Does running one Virtual Machine on a HYPER-V box make sense?

I am considering running HyperV for all my servers, because backup and disaster recovery plans are easier, when I can move the images around to any hardware and not have to worry about drivers. ...
6
votes
6answers
303 views

Is it possible to have a Single Anti-virus program for many VMs?

Sorry if I am asking a dumb question. Generally We use a physical server and create multiple virtual machines on that.(I am addressing the most simplest scenario) The operating systems and the ...
6
votes
3answers
23k views

RAID 10 or RAID 5 for multiple VMs - what is the best choice?

I have just ordered a new rig for my business. We do a lot of software development for Microsoft SharePoint and need the rig to run several virtual machines for development and test purposes. We will ...
6
votes
3answers
2k views

When is sustained 100% CPU utilization not a worry?

Please help refine a discussion going on in our shop. Consider the following scenario. There is a Microsoft VPC running several apps and services (Windows 2003 server). The server has two or three ...
6
votes
2answers
24k views

Running Mac OS X on Hyper-V

I have my workstation setup with a Windows Server 2008 running Hyper-V. Now I really want to install OS X for testing purposes. Have anyone had any success running Mac OS X in an Hyper-V environment? ...
6
votes
3answers
5k views

All sub-domains to one IP in hosts file?

I've got a VirtualBox VM running with host-only networking. This VM is running Apache, and I want to setup a bunch of name-based virtual hosts in it that can be accessed from the web browser on the ...
6
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3answers
215 views

Can I let my users create VM's as they wish?

In my dev team now, there has risen a request to be able to create/run VM's on demand. What they are asking for is a system/method/tool that they can select the following: CPU's, RAM, OS , Hard disk ...
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2answers
6k views

Number of logical processors per VM?

I have a server (quad core) running Windows Hyper-V Server 2008 R2 with two Windows Server 208 R2 Standard guest virtual machines. I've noticed the number of logical processors setting (under the ...
6
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2answers
3k views

VirtualBox guest network lost after host disconnects

I am running VirtualBox both on a Snow Leopard OSX host machine and on a Windows Vista host machine. Whenever my host machines lose internet connection the guest machines seem to lose internet ...
6
votes
1answer
218 views

virtual disk image - file or partition

I'm looking at the differences between using a file versus a partition to store a virtual disk image in VM use. The common knowledge is that partition-based images are faster than file-based images ...