Virtualization is a group of software technologies that allow abstraction between layers of a system. This allows separation between the logical layers of the system, providing isolation, flexibility, and/or the ability to run more than one at a time. This differs from most traditional systems where ...

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2answers
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Difference between KVM and QEMU

I have been reading about them for sometime. As of now I have a clear understanding of what they do. KVM supports hardware virtualization to provide near native performance to the Guest Operating ...
16
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5answers
3k views

Best Practices for virtualizing servers onto the SAN?

Alright, so I want to start leveraging my SAN a little more than I have been, and at the same time, take advantage of ESXi. Currently, I've got an array of Dell PowerEdge 1955 blades connected to a ...
21
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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?
7
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6answers
3k views

hardware recommendations for a DIY storage system based on ZFS [closed]

Looking to make use of old server lying idle as a proof-of-concept ...here are specs Dell PE 2900: Xeon 5110 - 2P, 12 GB RAM, 8x 300 GB 15K drives, Perc 5i+256 MB cache what additional h/w would be ...
13
votes
4answers
749 views

Are production servers running as virtual images a good idea?

What are the risks of running a production web server and database in on a virtual server? Currently we are thinking of using VM Ware server. It seems like a nice solution that will lead to easy ...
8
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2answers
5k views

KVM on Illumos (OpenIndiana vs. SmartOS)

I'm considering virtualizing a number of guests onto a single server running a recent port of KVM to Illumos. It sounds like my two primary options will be OpenIndiana and SmartOS. The distribution ...
14
votes
4answers
28k views

KVM: Which CPU features make VMs run better?

We are using Ubuntu 12.04 with the following parameters: Dell R910 Kernel 3.2.0-25-generic #40-Ubuntu SMP x86_64 x86_64 x86_64 GNU/Linux kvm 1:84+dfsg-0ubuntu16+1.0+noroms+0ubuntu13 qemu-kvm ...
15
votes
3answers
8k views

How much overhead does x86/x64 virtualization have?

How much overhead does x86/x64 virtualization (I'll probably be using VirtualBox, possbly VMWare, definitely not paravirtualization) have for each of the following operations a Win64 host and Linux64 ...
5
votes
2answers
6k views

Backup of KVM guests when using qcow2 disk files

I got a Ubuntu (hardy) system used for virtualization using KVM. Each guest got it's own qcow2 file used as disk. Guests are running Ubuntu (hardy). What would a good backup strategy be for such a ...
18
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2answers
1k views

Can a virtualized machine have the CPU and RAM resources of multiple underlying physical machines?

We are studying implementing some virtualized servers here, but we don't know what will be better suitable for us. Some folks are saying better have two huge servers, and others are saying have like a ...
26
votes
4answers
741 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 ...
18
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3answers
3k views

Virtual vs Physical Servers

I'm after a second opinion; and apologies if this has already been answered (point me in the right direction). Different factions within a project I'm on are engaged in a holy war between virtual vs ...
9
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6answers
965 views

Accurately trending random I/O performance for capacity planning

Where I work we have a numerous "big iron" servers which are used used for hosting many virtual machines using a Xen Hypervisor. These are typically configured with 32GB RAM, Dual Quad core processes ...
14
votes
9answers
16k views

Is it possible/advisable to run VMware Server ESX/ESXi on a laptop?

The idea of having a small footprint hypervisor as the primary OS on a laptop or desktop where every "real" OS is a guest appeals to me. Now I realize this software is more typically used on blades ...
5
votes
5answers
3k views

Is it realistic to run Windows Server 2008 with 1GB of RAM?

I am just about to "invest" in a cheap Windows 2008 VPS ($30 per month!) which comes with 1GB. Before I do that I thought I would ask if its realistic to expect a usable server with only 1GB of RAM? ...
4
votes
4answers
11k views

HP dl170 g6 and LO100 (iLO) - Can't boot from virtual media

I'm trying to make an HP DL170 G6 server boot via the "virtual media" feature. The system doesn't even try to boot from the virtual media, it seems unable to see it! Here's the test we've been doing: ...
4
votes
3answers
2k views

Is KVM stable enough for production use in 2011?

We are planning to virtualize the existing infrastructure by an open source virtualization solution. KVM and Xen are on the final list. Big cloud players are still using Xen, and we found that KVM is ...
4
votes
2answers
2k views

How to make SQL Server 2008 redundant?

At the moment I'd like to combine my departmental SQL Server into one big SQL Server 2008 instances spread across two servers (for redundancy reason). How/what is the best way to approach this ? is ...
4
votes
2answers
3k views

Running an Active Directory Primary Domain Controller as a virtual machine?

Should the Active Directory PDC always be a physical machine or would it be okay to run it in a VM? What are the implications/trade offs/gotchas? As a corollary to this, what about running a physical ...
2
votes
3answers
2k views

How to run OS X (Leopard or Tiger) in Windows?

Is there a way to run Mac OS X (Leopard or Tiger) in Windows on a virtual machine? I have 2 GB of RAM and a 2 GHz processor. My processor is an 32-bit AMD, but I don't think this will matter because ...
0
votes
6answers
6k views

How we build private cloud computing in my organization

I'm young admin in some organization, I would like to know how we prepare private cloud computing. Like what cloud computing consist of ? Regards Pond
9
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3answers
5k views

Is there danger to virtualizing a router?

I had read on a few forums about pfSense that said it was dangerous to virtualize pfSense. The reason that was stated was an attacker could use pfsense as a spring board for an attack on the ...
9
votes
3answers
4k views

use LXC under heavier virtualization (Xen, KVM,Hyper-V,VMVare)

Is it possible to use LXC under heavier virtualization (Xen DomU, KVM, Hyper-V, VMVare) ? I would like to use it as security (isolation) tool, the ability to limit resource consumption is not priority ...
9
votes
3answers
4k views

Is the Amazon EC2 instance id unique forever?

We're using amazon EC2 and we want to keep track of instaces. Is the Amazon EC2 instance-id unique forever? i.e. If a VM has an instance id of i-12345678 is there a guarantee that when that instance ...
8
votes
2answers
2k views

Adding new virtual disks to a RHEL host in ESX “live”

I'm sure I've just missed which tutorial/manual page covers this, but how do you add get the guest OS to recognize that you've added new drives to it without a reboot? I have a RHEL5 guest running on ...
4
votes
10answers
17k views

Which Linux distribution runs smoothly in Sun's VirtualBox?

Apparently some distributions do not run smoothly in VirtualBox. For example I installed Fedora 11 and I couldn't configure monitor's screen resolution to more than 800x600. What distribution run ...
3
votes
1answer
849 views

What is the recommended method to prepare Red Hat/CentOS 7 templates?

If I need to deploy Red Hat 7 from template, I would like to take the recommended steps to make my "golden image" clean. It should boot to the first boot prompt and guide the user through the typical ...
3
votes
2answers
7k views

KVM and virtual to physical CPU mapping

I'm a relative late comer to the virtualistion party, so you'll have to forgive me if this seems like an obvious question. If I have a server with 12 cores available, does each KVM guest have access ...
3
votes
1answer
3k views

KVM network bridge with public static IP for both host and guests

I have a Ubuntu 10.04 server with 2 public static addresses. There is a KVM guest (also Ubuntu) installed and running. What i want is to give the guest an IP of the host, so that both machines have ...
3
votes
8answers
13k views

How to find out if a Solaris machine is virtualized or not?

I have a set of machines and want to know how to find out if a given machine is virtualized or not. Any commands?
2
votes
1answer
113 views

VMWare: Are long running snapshots really THAT bad?

This is ESXi 5.5. I know that the VMWare KB is very against long running snapshots, however I do not know of another way to do this. Let's say I have a base Linux system and want to spin up a unique ...
2
votes
1answer
15k views

How to change a VM from split across multiple .vmdk files to a single one or two?

I have a VM with 3 partitions. One main one, one for swap space, one for storage. However, there are dozens of .vmdk files. Some of those .vmdk files are very large (over 1 GB), but the majority ...
2
votes
2answers
2k views

Mount LVM within a disk image

I have a disk image that I made with KVM. The partition layout inside the disk image is as follows. [root@centreon01 2tb-external]# fdisk -lu vdisk1.img Device Boot Start End ...
1
vote
2answers
11k views

How to get a CLI for a virtual machine on XenServer?

I created a Debian Lenny virtual machine as described on the manual. How to control it? It has no IP since my LAN has DHCP disabled. If it only had a static IP and SSHD enabled I could just PuTTY it. ...
14
votes
10answers
6k views

Are there any good reasons for disabling hardware-assisted virtualization?

We've had a number of servers from Dell recently, all of which have had hardware-assisted virtualization disabled in the BIOS. As far as I know hardware-assisted virtualization is a good thing - so ...
11
votes
1answer
4k views

Read/write access for passthrough (9p) filesystems with libvirt/qemu?

I have recently started experimenting with the support for passthrough filesystems in recent versions of KVM/QEMU/libvirt. Making the filesystems available for read access has "just worked", but I'm ...
6
votes
5answers
541 views

Virtualizing Microsoft SQL Database server

My company is looking to virtualize our Microsoft SQL server. I read on another question that databases on VM's suffer from a IO bottleneck which is not very good for us. But I was wondering if ...
5
votes
4answers
1k views

vCPU performance between 1 or 2 vCPU's

Within virtualisation (Predominantly VMware) is there a performance advantage using either 1 CPU with 4 cores or 2 CPU's with 2 cores? Let's assume the application running on a VM can use two CPU's.
5
votes
1answer
2k views

Does kern.hz still have any relevance in FreeBSD if “dynamic tick mode” is enabled?

I'm running a FreeBSD 9.0 setup as a virtual machine in a KVM setup. In previous versions of FreeBSD it was common to force the kern.hz setting to a lower value so that the virtual machine does not ...
5
votes
7answers
773 views

Make a copy running VM-ware Virtual Machines

I want to backup my virtual machines while they are running, is it possible to do this without buying more VM-Ware products? They are running on CentOS 5.2.
5
votes
1answer
623 views

Virtual vs. Named SQL Instances

What are the benefits to using virtual as opposed to running multiple instances of SQL on a box?
4
votes
2answers
362 views

How do I make all Xen guests use their host clock value?

I've set up Xen server under Linux with several guests running, and all was well. After some time I've noticed the clock on the server drifted away, so I installed 'ntpd', and the clock was back to ...
4
votes
2answers
302 views

Migrate VM from Virtual to Physical Server

I’m after viewpoints on my situation from my fellow sysadmins. I think I have thought of the points, but want someone else’s opinion. I have an ESXi5 Cluster consisting of 5 Physical machines: 4 in ...
4
votes
8answers
17k views

How should I convert a physical drive to a VHD for use with VirtualPC?

I have the hard disks from a PC that was happily running Windows Me until is it suffered an unknown hardware failure. The drives are intact, and can be mounted and read on other PCs. We have data ...
3
votes
2answers
1k views

When NOT to use virtualisation?

When virtualisation was new, we tried to virtualise everything, but then we noticed use cases where the our virtual machines were much slower than a bare metal. For us, we use the following rules ...
3
votes
2answers
871 views

Dedicated ip's for xen guests

I'm having a hell of an issue getting networking working in Xen on Ubuntu Server. Our server has a few public IPs (/29) that are all added through eth0 aliases. E.g. eth0 - main ip eth0:0 - first ...
3
votes
2answers
761 views

Can an ESX server under heavy load cause cpu spikes on guest VM's?

So we have a number of vm's running on an ESX 4.1 server for product testing. The ESX Server is at times under heavy load. We've been experiencing high CPU levels during some use cases, but we can't ...
3
votes
2answers
15k views

Can't ping host from vmware guest using bridged networking

Host is Windows 7 Guest is Ubuntu 11.04 Network adapter is wireless I can ping other computers on the network but not the host. No firewall are involved. Sniffing the traffic with wireshark it ...
3
votes
3answers
1k views

KVM “live migration finished” detection

I'm using KVM (through libvirt actually) for a research project. We're live-migrating a virtual machine between different subnets, so after the migration the IP address and routing tables have to be ...
3
votes
2answers
383 views

Should our web-app go Cloud or multiple VPS?

Let's say we have a web-app and there's an automated/under-the-hood process which updates the DB. At the moment, they all ran in the same server. We'd like to separate the batch-process from the ...