[Info-vax] VMware

[Dave Froble]

On 12/10/2019 1:26 PM, Grant Taylor wrote:
> On 12/10/19 1:42 AM, Dave Froble wrote:
>> But backing up a SAN is probably much easier than backing up 1000
>> stand alone systems.
>
> You don't "back up the SAN" per say.
>
> Think of the SAN as really fancy and long SCSI cables that move the
> disks out of the machine to somewhere else in the data center (or
> possibly even world).
>
> Backups have to be coordinated and in concert with the systems.  They
> may be taken from the SAN side, or over the SAN (Fibre Channel / iSCSI /
> et al.) fabric.  But the host is involved with the backups.
>
> You can't realistically copy / snapshot the SAN without having any input
> on the state of each (remote) disk, or LUN in SAN parlance, from each
> and every system.  —  Well, you can, but it's likely to be worse than
> crash consistency.
>
>> But what are the applications that can exist in such an environment?
>> That is where I get lost.
>
> Virtual Desktop Infrastructure (VDI) is a good example.  Instead of
> having Windows (et al.) running on all the desktops and wasting
> dedicated resources, you can run Windows in VMs with aggregate
> resources.  So, that accounts for a LOT of VMs if there are (were) a lot
> of desktops that are now GUI dumb terminals.

Ok, let's look at this.

What is a GUI dumb terminal?  Most of the ones I see are rather cheap 
desktop PCs using network storage.  The only advantage I might see 
running such in VMs is the ability to spin up a new VM with the OS and 
apps ready to go.  Still gonna need the "GUI dumb terminal".

Now, if the desktop user is doing something very CPU intensive, perhaps 
the VM would give less performance?

Some apps can be very CPU and video intensive.

Of course, none of this matters.  If the potential customers tell Clair 
they want to run VMS in VMs,  The smart money is to give the customer 
what he wants, and, collect lots of support money.

> As someone else pointed out, many applications are written with the
> assumption that they are the only thing running on the system.

All I'll say about that is that isn't how I learned to design apps.

>  So it's
> quite common in the Windows (and sometimes Linux) world to have a system
> per service.  Or more likely multiple systems per service application
> stack.  So rather than having physical system sprawl, more of these
> things are happening in VMs.


-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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