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

[Simon Clubley]

On 2016-06-25, Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
>
> OpenVMS has not integrated the MOUNT command or the mount system 
> service with mount points or links.
>

The MOUNT command as currently implemented (and the underlying
monolithic mass of filesystem code in the kernel) is not exactly
VMS's best selling point.

> OpenVMS lacks a volume manager.
>
> OpenVMS support for storage device management and storage device 
> swapping is limited at best.
>

OTOH, you can do things with volumes in VMS clusters, especially when
things go wrong, that you can't do elsewhere.

The terms "volume manager" and "storage device management" cover a wide
range of areas. So that I understand you, what _exactly_ are you looking
for (with examples if possible) with the last two items ?

> The configuration and related commands are manual, file-based and the 
> associated commands and syntax and configuration required (for 
> configuring USB devices, for instance) tends toward arcane and manual.
>
> Then there's that MOUNT — which is useful for other purposes in the I/O 
> system — is currently tied to disk and tape storage, and to specific 
> disk formats.   That design and that limit is not a surprise, but more 
> than a little of the underlying flexibility around ACP handling (yes, 
> ACPs are undocumented) was lost to developers here.  But I digress.
>

IMHO, I agree with you on this one. Based on what general knowledge
I know of how it's implemented internally (I've never seen the VMS
source code), MOUNT internals are a disaster area if you ever wanted
to implement general mount support in VMS for a variety of filesystems
in the way that it's possible in Linux (for example).

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.

Simon.

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