Posts tagged host
Server and Backup Layout
Dec 22nd
Both the master and slave servers reside on a host machine. Clearly the servers are virtual machines. Its strategic to use virtual machines because the host machine remains useful for a variety of other tasks. The virtual server compartmentalize the functions to a discretely backupable file. In my particular arrangement the master server is synchronized with the slave server. The slave server has the same applications installed as the master. A fully functional apache web server with php and mysql support. The mysql database is synchronized as a replicate in real time, and rsync is used to sync the apache web root. In the rsync function I skip the wordpress and wiki config files, in which I reference the mysql server on the slave machine. Doing so allows server2 to be a drop in replacement for the master just by switching the port forwarding settings in the router. I would have to reconfigure my.cnf as the master in such a transplanation. The mail server has spamassassin and clamav installed on master and slave and /var/mail are synchronized to keep a relatively real time backup.
Then once a day the slave server is backed up. Vboxtool handled this seamlessly. Vboxtool stops the virtual machine, transfers it, and automatically restarts it. The initial backup is done to backup1. Then rsync is used to backup the home folder on my host system. I also use the computer for my own personal things, which are effectively backed up to backup1. Then, subsequently, the host initiates an rsync of backup1 to backup2, then to backup3. I have a rsync duplicate of backup1 on backup2 and backup3.
The host also is a MythTV server, and backup3 is the client that is subsequently connected to the TV. I have my various hosts relatively diversified and multitasked.
VirtualBox – Peaking Interest as a Serious Competitor
Dec 16th
I’ve said for year VirtualBox was good stuff. I’ve used it since it was previously owned directly by Innotek. Now that Sun has purchase the relatively small European company, the software has exploded with new features and stability. Years ago usb support was in its infancy. Now its robust. Years ago processor support was limited, now its fully SMP enabled. I like the nested paging option reducing ram overhead, and integrating guests into, rather than partitioning, the host. A while back there was problems with the host processor no syncing completely with the guest, causing load when no guest load was present. This was resolved a long time ago, and now running multiple machines only causes load on the lost when load is indeed in the guest. My system has run stably for a long time now, only requiring host reboots when new updates are available.
How can paid system compete with free? I can understand in a Corporate environment commercial support may be needed. In such an application I would imagine Sun provides commercial level support for their VirtualBox product. This is indeed the case for the paid systems of Vmware, Parallels, and others. But ultimately if in house tech support is up to the task VirtualBox is a free product. This also allows for people to get their hands on it for learning purposes. I have learned VirtualBox by working it for years. I am very much discouraged to learn many software packages because I would have to pay for it. I will not be learning Windows 7 for this reason.
San Francisco – Desktop virtualization is one of those technologies that confound the experts. Just when you think you’ve got it figured out, along comes some interloping development to upset the apple cart. Most recently, that role has fallen to Sun’s VirtualBox, the plucky open source VM solution that’s quickly gobbling up the general-purpose desktop virtualization space left vacant by Microsoft and VMware. Users from the three major platforms — Windows, Mac OS X, and Linux — are flocking to VirtualBox for its scalability, robust networking, and bargain price point (it’s free).[Source]
VirtualBox Bridge and Tap no Longer Needed – Built in
Nov 3rd
With recent version of VirtualBox you no longer need to create a bridge and tap to enable host networking. In the settings panel of the virtual machine, select the network tab, and make sure that its set on bridged adapter. VirtualBox automatically creates a virtual ethernet adapter, and bridges it to the network of the host machine.
Bridging to the host network is necessary for the virtual machine to get an ip address from the router. Such a configuration is needed to communicate with the machine from the outside world. Because of this feature virtual machines can server website, and other services. I use my virtual machine to host this website, a visual ftp server, a wiki, and an EyesOS server.
There are other ways to forward individual ports from the host system to the guest, but then the ports on the host machine will not be accessible on the host; they will virtually represent the guest OS thus hindering connectivity with the host machine. There may be instances where this is what is wanted and more information, including instruction, can be found on this previous post.
The following is a screenshot of the network tab in VirtualBox. It had a bridge adapter option that will autobridge the connection to an existing ethernet adapter. Bare in mind that this is the screen from a Linux install of VirtualBox and it might be different in Windows. I remember in Windows you might have the option to create a virtual ethernet adapter, and then you can bridge the connection all in VirtualBox. Nothing needs to be done manually anymore, and everything can be done from within the VirtualBox configuration panels.
Here is a screen from Windows Vista. Go to the network tab of the virtual machine settings:
Then select the attach to drop down menu:
Then change the attach to, drop down menu, to bridged adapter:
LTSP-Build-Client Arch option not in Help
Jan 12th
To find the options for a command you type: command --help It spits out a bunch of options that you can use to tweak the parameters of a command. On the --help for the ltsp-build-client script is the --dist option, which I thought can be used to install a different distribution that the one you are current using on the host. For instance:
sudo lts-build-client --dist lenny
There is another option, and it is not specified in the --help. The --arch option allows the specification of different architecture than your host. For instance:
sudo ltsp-build-client --arch -i386
If you are using a 64 bit host, you can install an i386 client file system with this.
