Creating a space for Virtual Machines host

11 Mar 2008 22:43

Look at this:

http://dev.wikidot.com/farm-hosting

We want to make some Virtual hosting

I prepare the environment for it.

At first, it'll be the same server like the wikidot.com. In order to install VirtualBox i needed to:

yum install SDL.x86_64
yum install qt.x86_64
ldconfig
rpm -ihv VirtualBox-1.5.6_28266_rhel5-1.x86_64.rpm
(got from here: http://www.virtualbox.org/download/1.5.6/)
then:
/etc/init.d/vboxdrv setup

I added user vbuser with

• the group vboxusers (added by the RPM installation) — group of users that can run VirtualBox
• home: /vol/disk1/home-vbuser
• /home/vbuser links to /vol/disk1/home-vbuser

I started the VNC session with some gnome-panel and metacity for the user.

To do this again (in order one killed that) do:

vncserver

To stop:

killall Xvnc (this will probably kill all running virtual machines).

To connect to it just forward 5903 (this is :3 session of VNC) to localhost, in ssh:
ssh -L 5903:localhost:5903

and connect with a VNC client to the localhost:3

this way you don't transfer the plain password via the network. (the plain password goes through the SSH tunnel).

I created some test machine with a UbuntuServer on it (version 7.10 Gutsy Gibbon i386!!) and needed pkgs for wikidot.com (and the source from svn).

• RAM: 750MB
• disk: 20 GB auto-resize, LVM, guided partition scheme
• network: NAT — change to tun interface

NOTE

This does not work out of the box, we must exchange the kernel like described here: http://tombuntu.com/index.php/2007/09/05/making-ubuntu-server-work-in-virtualbox/

Rescue the system, go to sheel and then:
mount /boot
apt-get remove linux-server
apt-get install linux-generic

then boot from the disk and press ESC when GRUB boots, select generic.

TODO

install OSE version.

Comments: 1

Snapshots Of Filesystems Under Linux

07 Mar 2008 21:47

Today I've learnt about making snapshots of regular filesystems in Linux.

First of all, this is a link to the article I've found and seems to be quite OK: http://howtoforge.com/linux_lvm_snapshots_p2

The idea is simple. We have to:

1. Have LVM partition
2. Set up some (I believe this is not limited to standard ext3) partitions on it
3. Prepare some place for backups (over network or on a separate disk)
4. Then at any time, we can just create a snapshot - this does not really consume MUCH resources — but consumes SOME.
5. This takes not more than 1 second and creates a device/file/something that is an image of the filesystem in the exact moment of creating the snapshot.
6. Having the image (snapshot) we can do anything with it (like with a block device) — mount (and backup the files), create a raw-copy, export to another machine, clone, whatever.

Notes

• The author believes one can safely restore a backup without even restarting services.
  • Will we need to rely on this? 60 seconds of down-time is acceptable and guaranties that nothing bad happens.

Comments: 1