Lee Marzke on 5 Dec 2009 20:37:48 -0800

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Re: [PLUG] Virtual Setup Suggestions Wanted

These questions may help you decide.

>I'm thinking of replacing most of my servers with a single machine

If you have more than 4 guests to run on one host, I can't recommend
VMware server
which is old technology ( it used to be called GSX server )

1. ESX or ESXi - no base operating system required.  ESXi is about 300Mb
    more security at the ESXi layer,  because so little is installed.

2. ESX - Intel VT or AMD-V CPU not required, optional.   This is not
true of many
   of the other Hypervisors.

3. NOTE:    ESX 4.0  requires a 64bit CPU !

4. ESXi installes from CD in 10 min,  with NO configuration except for
    IP/GW  and admin password.   ALL the configuration is in the VM's
    themselves ,  or higher level stuff in Vcenter server.

    If you have external NFS / iSCSI mounts,  these have to be attached.
    If you have more then on NIC, these need to be activated/named.

    So you generally do NOT need to backup ESXi,  only the VM's themselves,
    the external NFS and Lan Info, and Vcenter server if you use that.

If you are going to run more than 3/4 guest VM's you will likely need more
than 4GB of RAM on the host anyway,  so you will need a 64bit host OS or
ESX to manage that much RAM.

If your only running 2 or 3 VM's memory management isn't so critical,
but as you
run more guest VM's  memory quickly becomes the limiting factor.

ESX is very good at sharing memory pages ,  and forcing VM's
to release unused memory with the 'balloon' memory driver.  So
this means you can run many more VM's with the same host memory

see:  http://tinyurl.com/ygk4jhl

In my case, I've chosen ESXi  ( free) version because many of my clients
run the full Vmware Vsphere suite,  and I'm evaluating the recently added
disaster recovery options, etc.

>ESXi seems pretty cool, but it is worth bothering with if the management tools 
>are costly? 

That's a slight misconception,  you do get management tools but they
are limited (  Each client can only attach to one ESX host )  So you
can even run multiple ESX hosts, but need a separate client for each.

You do get VM snapshots, CPU/Disk/Memory usage graphs, NFS/iSCSI
mounts,  virtual switch

The downsides of  running ESX (free) are:

1. You don't get templates and can't clone them.  Need to run Vmware
    on an instance to clone it.

2.  You need 1 or 2 windows boxes or VM's to manage it .  
       (1) vmware client installed on Windows to manage ESX directly,  or to
             attach to Vcenter Server.

       (1) optional windows box to run Vcenter server.  This
consolidates info
       from multiple ESX hosts together, and also serves to monitor each
       ESX host for high availabiliy HA (hearbeat),  centralizes logs,
       authentication, etc.   It also manages templates and cloning.

3. No support for Vmotion/ HA ,  Storage Vmotion without Vcenter Server.

In any case,  the installation and use of ESX and Vcenter are almost trivial
and you will be running in under a day,  which I can't say about the other


Casey Bralla wrote:
> Lee, thanks for the info.  I was rather confused by he VMWare web site (didn't 
> know what was free, and what was $$).
> ESXi seems pretty cool, but it is worth bothering with if the management tools 
> are costly?  I'm looking for a zero cost option.
> On Saturday December 05, 2009 5:04:46 pm you wrote:
>> Casey,
>> You left out Vmware ESX which is now free.
>> The differences from VMware Server to ESX are:
>> - No underlying OS,  it installed to bare metal.
>> - ESX is more efficient at sharing common memory between similar VM's (
>> such as multiple
>>   Linux OS's )
>> - ESX can run just about any Guest OS,  even without Intel-VT or AMD-V
>> cores.
>> - ESX can easily mount external storage vis NFS or iSCSI
>> - ESX has a build in Linux command line,  while ESXi is much smaller has
>> has no command line.
>> - Both ESX and ESXi are managed by a Vmware Client,  you can't manage
>>   them from their console.
>> - ESX is picky about hardware - limited support for NIC's and Disk
>> drivers.  See the info
>>   in the slides below.
>> If you running production boxes,  you really should think about having 2
>> hosts minimum
>> and live migration support.   Yes you need a SAN for this but you can
>> use OpenFiler or
>> something like IOmega Storecenter Pro ix4-100
>> There is no question that VMware is more expensive ( may be 2X or more )
>> than the other products,  however you won't need to do any scripting.
>> All the Vmotion ( moving
>> machines between hosts while running )  just works out of the box.   You
>> also get a disaster
>> recover option to backup a machines VM disk ( while running ).
>> To Eval, just install ESXi without a license, and install  VCenter
>> Server without a license and
>> you get o play with all the Enterprise features for 60 days.   You do
>> need a Windows VM for
>> Vcenter server, and a Windows VM for the VMware Client.
>> FYI,
>> Screenshots of many of the Hypervisors  from PLUG Norths panel
>> discussion are here:
>> http://plug.4aero.com/Members/lmarzke/plug_virtualization
>> I currently run about 6 VM's  ( mostly Linux web servers )  on a  Dual
>> 2-core Opteron
>> 1U server with 12GB RAM,  and it has been flawless.
>> Lee
>> Casey Bralla wrote:
>>> I'm thinking of replacing most of my servers with a single machine
>>> running virtual servers.
>>> I'm looking for suggestions from the group on which hypervisor to use.  
>>> here are my current thoughts:
>>> Virtualbox
>>> 1.  I already know it well from the desktop version
>>> 2.  I could use the open-sourced version, so no licensing issues
>>> 3.  Requires a full GUI to run under (at least to run it easily)
>>> 4.  Requires a normal Linux distro to hold the hypervisor
>>> VMWare Server
>>> 1.  Not open source, but free, and likely to remain available for a good
>>> while 2.  I'm not that familiar with it
>>> 3.  Requires a normal Linux distro to hold the hypervisor
>>> Xen
>>> 1.  I'm not at all familiar with it
>>> 2.  Would need a new CPU ($$ - I've got old hardware) to enable it to run
>>> without a separate Linux distro as hypervisor
>>> 3.  Doesn't produce a "pure" virtual machine unless you have a modern
>>> CPU, which I don't have at the moment
>>> QEMU
>>> 1.  I'm not familiar with it at all
>>> Ideally, I'd like to experiment with the system, then purchase some
>>> upgraded hardware to run in production.  That pretty much screws Xen.  I
>>> really like Virtualbox, but would prefer for the virtualizing software to
>>> be the hypervisor.
>>> Any suggestions from the group?

"Between subtle shading and the absence of light lies the nuance of iqlusion..."  - Kryptos

Lee Marzke,  lee@marzke.net   http://marzke.net/lee/
IT Consultant, VMware, VCenter, SAN storage, infrastructure, SW CM
+1 800-393-5217  office         +1 484-348-2230               fax
+1 610-564-4932  cell           sip://8003935217@4aero.com    VOIP

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