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ubuntu, kvm: some thoughts!

I have a KVM host and some KVM guests... All are Ubuntu guys.
Added by almost 4 years ago

KVM is a very interesting idea, but I experienced it in last month and finally get boring with it :) In fact it's Ubuntu which made me annoyed :)

First, each guest has its own operating system, package database and keeping guests up to date requires some efforts. The bad stuff is that Ubuntu causes a lot of security issues (see http://www.ubuntu.com/usn/). Ubuntu's Apt even has vulnerabilities as described in http://www.ubuntu.com/usn/usn-762-1. Such a good package manager :) Being lazy I setup a cron job to upgrade the server automatically each day and a local notification using `mailx` but I didn't receive any messages via email. May be the default `mailx` setup is wrong. So I should check something in empty log file in /var/log/mail*. Lol, ubuntu/mailx is great!

Second, installing unofficial packages on Ubuntu is really tedious. If you install freenx or FDS, you should use quite strange repository whose security keys isn't valid. I must accept a strange key, or not. This strongly means that my system is going to accept bad binary packages. There is no other way. Moreover some documents are very out-of-date or unmaintained. For e.g, FDS guides causes lot of troubles. In fact, I cannot get FDS work with that guide. Such a good guide!

And though I tried my best I couldn't get my freenx work :) So I just ignore it temporarily. On my previous Arch Linux, it only take minutes to get FreeNX server/client connected. Uhm, may be that Ubuntu makes me fool and stupid. Thank you, Ubuntu!

Third, KVM guest eats so much resources. I must use about 2.5GB (on guest) of hard disk (the qcow2 file) to save about 340MB of my real data. You may say that 2.5 isn't a problem. Yes, you're right. Until you have to do your guest backup via network. Instead of backing up my data, I have to backup 2.5GB of extra stuff and so heat my router :) Why do I have to backup the whole guest? Because if I just want to backup my data, I shouldnot use KVM solution.

KVM guest eat not only hard disk but also the memory. If you run a web server on guest, you must consume two type of memory: for the web server, and the guest system. If guest has some free amount of RAM it never gives back to the host. Guest acts like a selfish guy.

If you want a Ubuntu system, I may setup a KVM guest for you. Just for you and you have to maintain it yourself (don't ask me anything, please). If I have my own servers, I'd like to use Operating_system-level_virtualization (Xen, Linux VServer, or FreeBSD Jail). And if I want to keep my life healthy with maintenance jobs, I should keep myself away from Ubuntu.


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