[Info-vax] VSI OpenVMS V9.1 Field Test beginning.

[Craig A. Berry]

On 7/1/21 9:22 AM, Arne Vajhøj wrote:
> On 7/1/2021 5:30 AM, Jan-Erik Söderholm wrote:
>> Den 2021-07-01 kl. 10:26, skrev John Dallman:
>>> In article <sbig2b$m5$1 at dont-email.me>, johnhreinhardt at thereinhardts.org
>>> (John H. Reinhardt) wrote:
>>>> V9.1 Field Test Release Notes:
>>>> <https://vmssoftware.com/docs/VSI-X86V91-RN.pdf>
>>>
>>> I don't know very much about VMS at the system management level. Section
>>> 1.24 of this document says that OpenVMS x86 does not support swap files,
>>> but does say that page files should be used.
>>>
>>> What's the difference between swapping and paging, on VMS?
>>
>> "Swapping" is for writing out whole processes to the swap-file.
>> "Paging" is for writing out individual memory pages to the page-file.
> 
> And I don't think it is a big deal.
> 
> To me swapping was something that in rare cases could be useful
> on VAX back in the 1980's. Since Alpha swapping has been an
> indication that the system was totally fucked up.
> 
> Nobody will miss the possibility of being in COMO state.

No one said there is no swapping, just that there is no swap file. I
thought it had always been possible for the pagefile to get used for
swapping if necessary, though I can't find any docs to that effect at
the moment.  So it's possible there is no swapping, but it's also
possible it's just done differently.

The swapper handles some special start-up tasks such as initializing
non-paged pool.  The new in-memory start-up image likely changed how
memory management works in the early phases of start-up, and may have
provided opportunities for simplifying or eliminating the swapper.