Timothy Murphy wrote:
> I just bought this very nice ThinkPad T20 through the list -
> it makes me realise how much bad behaviour I've been putting up with
> from my Sony Picturebook.
> The ThinkPad is running Slax, with vmware installed,
> so I thought I'd see what vmware is all about.
>> As far as I can see, the vmware documentation
> was written by and for aliens.
> Do normal people use vmware,
> or is it just for pointy-heads?
>VMware is very real yes.. They are a company owned by EMC and are very
much in existence providing a product that is very much production
quality as well as a recently released free version. Closed source but
we cant all have our cake and eat it.
Did you think otherwise? Wasnt there enough information on their website
to convince you that they are very real or maybe even virtually real?
(bad pun I know, sorry!)
Anyways, on to the product itself. Your mileage might vary as to whether
the product will perform as you expect.
If you wish to maximise the capabilities of your new hardware or wish to
run a legacy recently unsupported OS susch as Win98 on new hardware
which might not have drivers available then this is the product for you.
If you wish to create a test machine for whatever methods of destruction
you wish, you can do so. There are almost limitless examples as to how
any Sysadmin could find a use for it, even more so now there is a free
As previously noted, there are other Open Source alternatives available
such as Xen and Qemu.
As with all software it has its limitations. To give an example. I
recently bought a new server. Dual Core Xeon with 2GB of RAM and 730GB
of hard drive space. This machine was originally intended to be a
dedicated as a Lotus Domino server. the specifications are overkill for
this as I know but that was part of the greater plan.
The greater plan involved consolodating 4 servers in one. The server
came supplied with Windows Server 2003, for which we have the relevant
licenses. microsoft require CALS (Client access licenses) for each
Domino user if Domino runs on a Windows OS server. So upshot is that for
our 65 Domino licenses we also needed 65 windows CALS. Obvious course of
action to me was to use linux as the OS and only have to pay for the
Domino CALS. Yet as mentioned above, The hardware is a bit overkill for
the intended puropse.
In my charge are 3 rather elderly NT 4.0 machines. Each performs a
specific puropse. The hardware is all approx. 6 to 7 years old and with
event logs warning daily of impending hardware failure. It was my plan
to migrate these over to virtual machines on the one physical server.
Since we have licenses for Windows NT 4.0, the justification for
migrating these servers to Server 2003 could not be an option, nor was
Linux and Samba an option as they were not just file servers. Nor was
using NT 4.0 an option as the OS on the new hardware since it is now end
of life and no longer supported.
The final configuration of the new server is Windows 2003 Host OS, 4 x
Windows NT4.0 virtual machines and one CentOS 4,1 running our Domino
server. Performance is way above my original expectations. CPU usage is
pretty minimal. But it is not without its limitations. Now for the pros
Maximum usage of hardware (not using a sledgehammer to crack a walnut)
Able to use exsisting licensed software (albeit no longer supported)
Backups are easier as the tape drive is attached to the server and
therefore saves on network bandwidth. But at the same time more
difficult (See cons below.)
Able to reproduce a machine in minutes with copy and paste. If I want to
deploy a particular software upgrade I can test it on a VM first and not
have to worry about thrashing it since I can reproduce this VM in seconds.
One big huge single point of failure. If the host OS or indeed the
physical machine has a failure then 4 production servers (in my case)
are instantly out of action. A good backup strategy should be able to
counteract this if spare hardware is available since then it is only a
matter of setting up a host OS and restoring from backup but this will
take hours, but then again so do most restorations. Problem in my
scenario is that 4 machines are out of action!
There is a fine line between maximising resources and maintaining
availability but for us, so far so good.
We also use the Workstation product, again for legacy support. In our
case running a DOS based app in a Windows 98 VM which will not run on XP
(Corporate standard). In my experience I cannot fault it so far. once
you are aware of the limitations then you should be able to decide if
this is a solution for you.
I hope my example of using VMware in a production environment will give
you all some idea of its capabilites but as with everything else you
must be aware of the limitations.
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