[Info-vax] New filesystem mentioned

[Simon Clubley]

On 2019-05-13, Dave Froble <davef at tsoft-inc.com> wrote:
> On 5/13/2019 8:52 PM, Arne Vajhøj wrote:
>>
>> But now you are assuming that ZFS is just an ODS-something format and
>> that RMS, SYS$QIO(W) etc. just runs on top of it.
>
> So far, I don't see any problems with such assumptions.
>
> RMS is just data, whether it's internal data, or user data.  It gets 
> stored on "disk blocks".
>
> I'd assume (bad habit) that if any file system was implemented on VMS, 
> that QIOs would be the method for access.  Now, QIO may need to know 
> some new things.
>
> For any file system to be implemented on VMS, it's going to have to work 
> as other file systems, else what's the use?  If low level code and all 
> new file accessing is required, the usefulness becomes much less.  Might 
> as well go back to physical I/O.  The purpose of a file system is to be 
> a lower level tool transparent to user code.
>

That's exactly how things work on Linux. Normal user programs don't
care what the underlying file system is.

On VMS, you may have to use special mount options to supply values
that the filesystem doesn't hold on-disk, but that's no different
to what Linux does with FAT32 (for example) if you don't like
the defaults selected for you by the Linux mount command.

After that, it's just another filesystem as far as a normal user
program is concerned.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world