[Info-vax] MOUNT and filesystems, was: Re: RMS record metadata, was: Re: Re; Spiralog, RMS Journaling (was

[Michael Moroney]

David Froble <davef at tsoft-inc.com> writes:

>> You should be able to write (for example) a FAT32 filesystem driver
>> from public documentation and use a MOUNT command to mount it in the
>> same way as you can with an ODS-2 volume.

>Why do you think that MOUNT should be able to handle some format that it 
>doesn't know about?

>Perhaps if you wish to implement a FAT32 filesystem driver, then you 
>should also implement the method(s) for mounting the filesystem.

File system support (other than relatively trivial transfer programs) in 
VMS need some knowledge by MOUNT for it to even know what to do about a
foreign format.  For the theoretical FAT32 filesystem, you'd need a /FAT32
paramater to tell MOUNT this is a FAT32 filesystem, for it to validate the
filesystem and launch an ACP to deal with the file system.

A while back, I did write enough code to recognize FAT filesystems, to
"MOUNT" it (a standalone program does this, not VMS $ MOUNT) and to fire
off an ACP.  The disk shows up as MOUNTed on VMS and trying to do anything
to it does properly poke the ACP, so a $ DIRECTORY DKxx: correctly dies
with the expected error.  The ACP actually doesn't know how to do anything
at all except to DISMOUNT it, and I probably won't be able to learn enough
to make it do anything useful.  And they pay me to do different things,
not this, this was just toy code.

Nob