UNIX for Beginners Questions & Answers

Still the best suggestion (for me) is openVZ and other suggestions don't accept because they did not develop specially for virtualization and they are multifunctional OS.
welcome to new hints
Thanks all.

My experience is that major Linux updates to PHP and Apache2 can and do break things.

It has to break things in many circumstances because, for example, the Apache2 configuration file for the latest version of Apache2 / PHP7 does not work with PHP 5.X versions, of PHP/Apache2, etc.

So, Apache2 will break during some major upgrades and so will PHP code.

Also, PHP code which is DEPRECATED in PHP7 will break when upgrading to PHP7.

You must be very careful upgrading if you do not want a lot of unexpected downtime; and if you are just doing the upgrade on your personal server, that might be OK; but if you are upgrading a production server, one odd config file change or incompatibility can ruin your day for sure.

What is related to the virtualization subject?

Because earlier in this thread people discussed various Linux distributions, so if you read the earlier threads about "breaking when upgrading" then you will not be confused, LOL, as people's replies are based on the facts, not just one subject line.

Virtualization is not some "magic word", it is an instance of a distribution of some operating system(s) and the performance is based on a number of things, including reliability and upgradability.

The original questions is more confusing than my reply:

"Best performance .... " ? That is a very confusing concept as well

One big distinction you might want to make when it comes to virtualisation is "para-virtualisation" versus "full-virtualisation".

The difference is that a para-virtualised system is aware that it is virtual. This means that it can forego some tasks a non-virtualised system would have to do:

i.e. a disk driver needs to check if the disk is still accessible, may have to cover for a block becoming bad, etc.. A fully virtualised disk driver thinks that the (virtual) disk it is presented is in fact a real disk and treats it accordingly. It will do all these checks i talked before. A para-virtualised disk driver would "know" that what seems to be a disk is in fact a file on some real disk and forego all these checks because the disk driver of the host system would carry them out anyway. This will make the para-virtualised driver faster and less resource-consuming. On the other hand it would mean that you have a system with a different driver and you can't simply copy your physical system to a virtual environment (or the other direction) without changing some things.

I haven't worked with OpenVZ for a long time, so i cannot say anything about newer versions. OpenVZ is (was?) such a para-virtualised environment which offers performance benefits compared to fully virtualised environments like VirtualBox, etc.. But basically it is (or was?) a very comfortable chroot-environment and the performance gain meant on the other hand, that you had only one kernel really running. This meant that you were not completely independent in chosing the system you wanted to run virtualised. If it is now possible to mix Windows- and Linux-systems on the same hardware node IMHO this means that they have switched to full virtualisation and this perhaps means giving up some/all of the performance advantages the para-virtualised system once had.

But without more clearly defining what you want to do a serious suggestion is not possible, as already has been said times and again.

I hope this helps.

bakunin