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

[David Froble]

Simon Clubley wrote:
> 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.

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.