[Info-vax] Reloading device drivers on x86-64 VMS

[David Froble]

Stephen Hoffman wrote:
> On 2015-03-08 23:22:29 +0000, David Froble said:
> 
>> Craig A. Berry wrote:
>>> On 3/8/15 8:17 AM, Stephen Hoffman wrote:
>>>
>>>> But yes, it'd be very nice to have the ability to unload and reload 
>>>> drivers.
>>>
>>> Shareable images too, while you're at it, but that's a different topic.
>>
>> Ok, what am I missing here?  Sharable images can be installed, 
>> removed, and replaced, right?
> 
> The files themselves, sure.  Easy to swap this, and if your application 
> processes restart themselves, your shareables will be found and used.  
> Things get more interesting once the shareable images have been 
> activated and are running, if you should want to remove or replace that 
> code.   Folks presently have to do that by running down a process, which 
> means loading shims or analogous, and accessing the results of the 
> transient code via global section, sockets, or RPC mechanisms 
> <http://www.grpc.io> 
> <http://h71000.www7.hp.com/doc/82final/6528/6528pro.html>, or other 
> such.  This for longer-running processes — that dreaded uptime — that 
> don't have mechanisms for rolling out changes, or for 
> checkpoint-restart, etc.
> 
> 

Some of these features being discussed are nice, and in some instances 
perhaps a bit helpful.  Might as well have them, if possible.

But for somebody running production (whatever that is) I don't see 
anything discussed so far as very meaningful.

If you're working on device drivers, you sure aren't working on a 
production system.  Not on any of mine anyway.

If you want to install a new version of a sharable image, if it's 
compatible with the old version, what does it matter how long before the 
old version isn't used?  If it isn't compatible, I think you got more to 
worry about than replacing a sharable image.

A production system is (by my definition) a system running acceptable 
applications, and there is no reason for emergency updates.  If you do 
have some required updates, they may require a new executable, or more. 
  Seems to me that's already covered with current capabilities.

I for one am not afraid of a bit of downtime and a reboot of the OS. 
Better if not required, but, no fear ....

All that written, yeah, VMS should have as much flexibility and 
capability as can be implemented.