[Info-vax] VMware

[Grant Taylor]

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.

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



-- 
Grant. . . .
unix || die