We all live every day in virtual environments, defined by our ideas

I am not a fan of virtualbox and only use it as a ‘sandbox’ / development / testing environment. I have seen many benchmark reports that would suggest that libvirt / kvm - qemu has an edge over virtualbox (when compairing performance and the host resources). Also it is worth noting that the host server is using a cpu that allows for hardware virtuailzation (VT-d).

@PParker I would be interested to know what limitations you have found with qemu. Depending on the host hardware and configuration, it is possible to provide near native performance.

Red Hat provides a good guide about tuning KVM hosts and sessions.
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-singl/Virtualization_Tuning_and_Optimization_Guide/

As an example of QEMU / KVM performance, I have found a YouTube video that demostrates a MS Win 7 guest running at 95% of the Linux based host.; https://www.youtube.com/watch?v=37D2bRsthfI (also read KVM VGA-Passthrough using the new vfio-vga support in kernel =>3.9 / Kernel & Hardware / Arch Linux Forums ).

Also, whilst I understand your issues about security of PAM user access, we both known that it is very easy to secure ssh sessions and control what the user has access to.

@alefattorini, yes I use Red Hats Virt-Manager (VMM). The are a couple of reasons I use this, the main reason is that it can connect and manage libvirt sessions from several host, also it is easy and fast to create and clone sessions / manage snapshots.

One requirement I have is that I have a 500gb hdd full with data that I want to mount on the host and pass through to multiple lbivirt guests.

Also, I have been doing some research about using containers (such as docker) instead of using vm and just wondering if anybody has any thoughts.

Read http://www.linuxjournal.com/content/containers—not-virtual-machines—are-future-cloud?page=0,1

VM is the only answer when you’ve got to use a different O.S. (windows anyone?)

docker and other containers are usefull when you need, for example, multiple version of the same sw on the same machine

they are (very) different tools with different aims

all IMVHO

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Qemu has missed the mark for me on hard drive limitations, and adding memory(mind you all my servers are maxxed out,both in memory and hard drive space) I have used it in unix and I personally dont like the way it sets itself up, it cannot handle multiple hard drives and hard drives over a certain size gives errors on all of my machines. I have also tried it on Unix(mac) it does the same exact thing, but that is your preference and your selection it provides what you need, I personally would use virtualbox and call it a day, it runs mostly everything with good efficiency, Qemu is what is comfortable for you, i am not knocking your use of it,it is what you like, i personally favor something else. I have tried to run Windows 7 on it, and it spits errors about not handling memory and hard drive space, I dont understand it, I even have tried it on PPC same thing… so i dont use it for that reason.

http://www.linux-kvm.org/page/Main_Page it’s not merely Qemu …

I will be looking at that later, last time i tried it was horrible, so this is new to me… i will read thru it …

Quick question, is there any point of creating swap partitions on guest VMs?

I have created a swap partition on my host server but wondering if to create swap on the VMs, are there any real advantages to a swap partition on a virtual guest?

Just been thinking about DNS for VMs. Wouild it be a good idea to add a master / slave option to the DNS settings in the web interface. Also is it possible to reverse DNS (x.x.x.in-addr.arpa) via the web interface?

It’s better to always have SWAP even on virtual machine but it will a little bit slower than normal.
If you really want the best performance, a good (and expensive) practice is to add SSD disks dedicated for the SWAP attached to the VM.
But normally this kind of configuration is not necessary.

What do you exactly mean? Maybe we can create another topic?

The DNS already does reverse queries, are you asking for a web interface to query the DNS server?
You can use the host command or dig.

I have created a new post for this topic
(The Domain Name Server is the Achilles heel of the Web. The important thing is that it’s managed responsibly)

Unfortunately for me I use Virtualbox for my development and also for my personal use, my server are running over virtualbox. I must agree that I have not a strong usage with many users.

In fact I have a server ‘all_in_one’ an octocore with a 32G of Ram and 8 Teras of HD. Probably you have understood the usage I have

HTPC/xbmc, Virtualisation, local repository, development…

Therefore I must have an X-server, movies in ascii art are fun the first ten minutes, but no more after.

I would use Proxmox but the kernel prohibits the usage of HDMI with sound, at least I need the kernel 3.2, and thus It remains lib-virt directly and Virtualbox…OK in a near future I will send a letter to santa and I will have a raspberry V2 behind my TV. (Santa if you read me)

Virtualbox is simple but with defaults, for example you must close all VM if you upgrade virtualbox…that is an issue :slight_smile:

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Interesing to see what other hardware / backbone infrastructure other people are using (might be a good idea for a new topic.).

32 GB of RAM and 8 cores (what speed are they running at?) seems a bit of an overkill for a server (unless you are running it within a datacentre environment!), but seeing that you are using your server like a workstation with a desktop environment / X installed, I can understand the need for the high specifications. Does your bios / cpu support hardware virtualization (either VT-d or IOMMU support)?

Out of interest, as you are running Nethserver within a Virtualbox environment, how many processors and how much RAM have you given to the Nethserver environment?

I am not sure of the minimum hardware specification for Nethserver, but I reckon that Nethserver could be installed and run on a minimum based PC (eg. 1GB RAM, 2Ghz single core cpu, 10GB hdd)

I have installed and running Nethserver / CentOS on a Duel core (2.70Ghz), 4GB RAM, multiple HDDs (30GB root partition 5GB swap), 2 wired NICs (eth0 and eth1) and 1 wireless NIC (wlan0). The actual pc is a IBM Lenovo (modal: M75).

Obviously, as I am not using any DE / X-server and only accessing the server via ssh and the web interfaces (using both Nethserver and Webmin admin panels), the system is using only a small amount of the PC’s resources.

There is already one :wink: feel free To post there

I moved a post to a new topic: I can’t run any guest VMs over bridge network

produit: AMD FX™-8320 Eight-Core Processor
capacité: 3500MHz
configuration: cores=8 enabled cores=8 threads=8
virtualisation instruction : amd-v
size: 7980MiB

MB
produit: 970A-UD3
fabriquant: Gigabyte Technology Co., Ltd.

All the time I have 4 virtualbox running machines on a debian 7 wheezy

  • SME Server
  • Centos6 Build Server
  • debian 7 local repositories for development (debian, centos, epel, smeserver, nethserver, mirror.de-labrusse.fr)
  • debian 7 for Jdownloader

After that I need to have more machines running for development, at least one by bug/feature tested or fixed and often I can play with 10 Machines or sometime more…ok you can pause a machine and start another one :frowning:

before that I had an AMD Athlon™ II X4 640 Processor but it was sometime too slow. In fact I don’t have time to waste and I don’t like to wait, therefore I have chosen a powerful (and not expensive) processor.

Actually the X server doesn’t waste time processor when I watch movies mainly because I use VDPAU with a little nvida card (less 30€).

produit: GT218 [GeForce 210]
fabriquant: NVIDIA Corporation

With that processor and the amount of ram, I have a nice sand box. Most of time I use virtualbox by ssh with an export display, but I have also phpvirtualbox if I need to manage quickly virtual machine or across the local network.

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@stephdl, sounds like a healthy set of specifications (I just visited Gigabyte website and had a look at the board details - looks nice!)

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Just had a thought, if you are running Windows/Linux as a desktop/workstation then maybe it would make more sense to have a duel boot workstation (using grub to select between the two OS)

I know it’s a old topic but

I have a concret exemple for @medworthy about if swap is usefull inside a VM

I had a VM was running in & out of memory and because of that was refusing mail from time to time. With SWAP I resolve the issue.

@PParker VirtualBox is nice; use it a lot inside of OpenMediaVault; but you can’t nested, which means doing VM under VM. As an example you can’t make a KVM Host inside a VirtualBox.

Voilà my two cents. :wink:

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I personally switched from virtualbox to proxmox since I reinstalled my server. At first I could think that proxmox is better than VB, but if you look deeply, VB gets some better options like when you clone a VM it is a full clone (mac address is not changed), with proxmox it is not possible, so I use snapshot to go back at the first state. An option could be to make a backup of the VM and restore it, however it needs so LONG time.

The usb catch is better in VB
The wide display of VM is better in VB

The killer features of proxmox are all the VM management (HA, monitoring, VM migration).

In short, if you are a developer, and you don’t have the need to keep a VM working a long time, Virtualbox is nice also.

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