[Koha] Some questions about virtualization.

[Tim Young]

I have done a fair bit with different ones of these.

1) Yes

2) I will spend most of my time discussing this below.  Skipping this 
answer for the moment.

3) Koha works fine on virtualized servers, so long as the host machine 
is powerful enough to run it.  For the most part, you never realize a 
service is on a virtualized server, unless your virtualization 
environment has issues.


Choosing a virtualization environment:

The first rule is to *use what you are familiar with*.  If all your 
techies are Windows people, use Hypervisor.  If they are all Linux, use 
one of the Linux ones KVM, Proxmox, etc.  If you already have a VMWare 
presence, then you can add Koha to your VMWare host.

Containers are a linux-only thing.  If you go to install them on 
Windows, it creates a Linux VM under which the containers run. 
Containers work very nicely if you have lots and lots of machines, or if 
you are really strapped for CPU power  But if you have never used 
containers before, the learning curve is a lot steeper than you might 
think.  Remember, not only do you need to get a server running, but you 
need to be able to back it up.


If you are starting into Virtualization, the first question is what 
operating systems do you know.  The Linux hosting options are very nice 
if you know Linux pretty well.  Proxmox, for example, is a paid-for GUI 
that you can use to access the free Linux KVM stuff.  Linux does that 
all for free, but the interface is either harder to set up, or very 
manual.  You can use an openstack or cloudstack, but those are very 
complex and awkward to maintain if you are new at virtualization.  I 
like Linux, and I use Linux VMs all the time.  But, more people prefer 
hypervisor or VMWare because they have much nicer user interfaces.  As 
nice as virtualization is, you need to get something you can manage.  No 
server is "turn it on and forget it."  All servers require backing up, 
upgrading, and the like.  With Virtualization, you want to be able to 
take snapshots and access the machine "console" if it has an issue booting.

Windows licenses are always a pain.  I think "understanding licensing" 
is the biggest complaint I hear from people who use Windows Hypervisor.  
And it can get fairly expensive.

The biggest complaint I hear from Linux people is the interface and 
trying to manage the machine from a Windows platform.

The biggest complaint I hear from VMWare people is that it is hard to 
manage the computer from a machine that you do not have everything set 
up on.  And, the VMWare licenses usually end up costing a fair bit more 
than you anticipated.

You may notice I did not mention Oracle Virtualbox as an option. Many 
people are tempted to use it since it appears to be free.  It does have 
a lot of features, but it does not scale well in the server world.  And, 
you are supposed to pay for it if you are using it for servers.  It is 
an awesome virtualization environment for testing and for use for 
yourself, but the free setup is missing a lot of features (like, 
starting VMs at boot) which you expect out of a server platform.  I have 
never use it in a paid-for environment; I am sure it would work well, 
but it is the one platform I have not used myself.

My 2c.

     - Tim Young

On 9/18/2017 5:03 AM, Przemek.KosiA at LightSys.org wrote:
> Hi
> I have some questions about virtualization.
>
> 1. Does anyone use KOHA on virtualized servers?
> 2. What solution did you choose KVM, LXC / LDX, VMVare, ProxmoxVE or 
> Docker containers?
> 3. Does it work on production servers or only on test servers?
> 4. Problems, challenges, thoughts?
>
> Tips, hints, guides welcome;)
> Przemek Kosinski