[Info-vax] New filesystem mentioned

[Simon Clubley]

On 2019-05-14, Dave Froble <davef at tsoft-inc.com> wrote:
> On 5/14/2019 11:19 AM, Stephen Hoffman wrote:
>> The Record Management System (RMS) metadata details have to be stored
>> somewhere.  Or reconstituted somehow.  Metadata such as that associated
>> with sequential, relative and indexed files will have to be persisted in
>> some file system data structure.
>
> It's always been my impression that the RMS metadata is stored in the 
> data records and directory entries.  Such as the two bytes (I seem to 
> recall) at the front of each relative file record.  Not any part of the 
> filesystem.
>

Where RMS metadata is stored is filesystem specific.

For example, with NFS, you can set things up so that the metadata
is stored in another small file alongside the real file.

>>  This gets interesting when adopting
>> some file systems such as the Microsoft FAT or ExFAT file systems,
>> ISO-9660:2013, ISO-9660:2017, UDF, or other more portable or more
>> transportable file systems.  The other systems would have to ignore or
>> to support the RMS metadata, or RMS and RMS-using apps would have to be
>> modified to remove or rework the related system and app-related metadata
>> requirements.
>
> I really don't understand this concern.  If directory entries contain 
> some RMS metadata, and I think they do, that can just be ignored by 
> things that do not need the data.
>

As Bob has already mentioned, the RMS attribute data is stored in
the file header for the ODS-2/ODS-5 VMS filesystems.

In a newly designed modular system, you should be able to store the
RMS data somewhere (ie: NFS) or fake it (ie: mount/undefined_fat).

Linux actually has a similar problem at the moment. FAT32 does not
support owner and group permissions so defaults are applied when
you mount a FAT32 filesystem under Linux. If you don't like the
defaults, you can change them using the mount command.

For me, this works just fine when I need to access a FAT32 filesystem
on Linux.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
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