[SAC] Server Planning

[Alex Mandel]

Now that the servers are shipping, we can clearly focus on developing
our deployment plan.

To help here is a slew of answers from OSL to questions I had posted on
the wiki page:
http://wiki.osgeo.org/wiki/Infrastructure_Transition_Plan_2010

On Tue Feb 16 23:36:39 2010, tech at wildintellect.com wrote:
> > Lance/OSL Team,
> >
> > The servers are on the way. See attached for details.
> >
> > The OSGeo team has decided on Debian Stable w/backports enabled, do
> > you have any instructions, or references for how to create a kvm
> > template image?

We'll have a base Debian Stable image setup for you already and then let
you configure it with the settings you need (with backports for
example).

> > Any suggestion on 32 vs 64 bit, we're split on the issue right now?

I'm setting up all VMs with 64bit to keep things simple. I would
recommend doing 64bit if possible as it does give you some other
advantages down the road.

> > As a side note, we are working on our deployment plan and have a wiki
> > page. Most of it probably doesn't concern your team except for our
> > discussion about the best way to do LDAP(will probably continue on our
> > current machines until we solve it) and Backups.
> > http://wiki.osgeo.org/wiki/Infrastructure_Transition_Plan_2010

Let me answer some of the questions at the bottom for you:

* Can ram be increased/decreased live?

No, not as far as I know.

* Can ram be increased/decreased via a web interface live or with power
  cycle?

Not web interface exists yet for what we'll be using but we plan on
having one eventually. A power cycle will be needed for a RAM change.
This could change down the road however depending on features that get
added.

* Is it easy to move VMs between the machines? Via web interface?

Yes with the cli, no web interface exists.

* Should the LDAP be hosted on one of the Host OS' for reliability?

Possibly, but I'm not sure where we can put that.

* Would LVM snapshot backups of virtual machines be a viable backup
  method?

Possibly, ganeti supports an export functionality which takes an LVM
snapshot, then runs dump on the filesystem. So you could use that while
its live in theory but I haven't tested that fully.

We generally just setup a normal backup process with our backend system.

* ext4 formatting

We could do that, but I haven't fully tested using ext4 with ganeti.
Ganeti doesn't really care what filesystem you use until you want to do
an import/export operation. The biggest issue is having support for ext4
in dump which I need to test. If you really need this we can do it but
I'd recommend ext3 for now.

* 32bit vs 64bit - in some cases smaller VMs with only 2 GB etc could
  perform better with 32 bit

See my statement above.

* default HD size? - remember to leave lots of room for /var, logs and
  database dumps even if there's not much in the VM

This depends on the use of the VM. Our "standard" is 10G per VM but this
is entirely up to you. We can also grow filesystems.

Another thing to note is that the partition layout for all of these VMs
need to be the same in order to allow for the export/import/install to
work properly. For now we're going with /boot, swap, / to keep things
simple.

What kind of an ETA do you have for getting this deployed? I'm pretty
swamped for the next month or so but I should be able to get this setup.
I'm also waiting for the GA relase of Ganeti 2.1 which should be fairly
soon.

Let me know if you have any more questions.

-- Lance Albertson Systems Administrator / Architect Open Source Lab