Is it possible and safe to update debian inside VPS?

Question

I have one semi-expendable (not production/mission critical) Debian VPS, which I use for my personal needs.

I have some problems with an applications new versions not working properly with old squeeze (I need to use some older packages, or older source code versions, which doesn't have some later versions features).

I am considering about upgrading Debian Squeeze to Wheezy. However I am not sure if that update is possible and would not break VPS completely (corrupt entire system image, some servers, DAEMONS down are OK as long they are fixable and ssh connection is working well).

Virtualization technology used on server is OpenVZ. AFAIK OpenVZ uses shared kernel which depends on VPS provider. I do not need to update it, but I have concern that wheezy will not work with old kernel. Kernel in server seems to be 2.6.32.

Are my concerns hold any truth? Is update feasible? Does anyone run in some kind of problems with updates like this?

Solution

For an OpenVZ VPS to change distribution and/or major release you would normally rebuild/reimage using whatever control panel your VPS provider has and choose from the list of Linux distribution and release/version templates they make available.

You lose all your data and configuration but it takes minutes to do and you then have a working VPS to update/configure as you like.

Looks like you can upgrade in place as well, though there could be problems migrating some configurations/data like nginx, mysqld etc, one way is:

sed -i 's/squeeze/wheezy/g' /etc/apt/sources.list
apt-get update
apt-get dist-upgrade

Ref: LowEndTalk : Debian 7.0 "Wheezy" released

Comments

[Ramhound]

Can you not just create a backup of the image and restore the working configuration if something goes wrong?

[Ramhound]

@lBr - Anything can happen. Prepare for the worst case. I see no reason why you shouldn't be able to update, unless of course, the update process for Debian itself is broken.

[IBr]

OK I will look into that.

[IBr]

By default they have debian 6 (squeeze), alternatives are Ubuntu 8.04 10.10, CentOS up to 6, fedora 15, Suse 11.4. Wheezy is not in list.

[Brian]

Send in a support ticket for them to create/add a template for Debian 7. While there is sometimes a little lag between a release and OpenVZ support Debian 7 has been supported for a long time (openvz.org/Debian_template_creation) Note that they have to make the template, it is not something you can do yourself.

[Brian]

There are even pre-create templates they can use/customize openvz.org/Download/template/precreated

[Daniel Alder]

Warning: There seem to be problems with Debian 8 "Jessie" (upgraded from wheezy)! There are also no templates available yet