[Info-vax] New filesystem mentioned

[Stephen Hoffman]

On 2019-05-14 16:53:08 +0000, Bob Gezelter said:

> With all due respect, RMS data is NOT included in directory entries 
> (reference: the ODS-2 specification OR McCoy sanitized version 
> published by Digital Press). If RMS metadata were stored in the 
> directory, VERIFY/LOST would clearly not be functional.
> 
> RMS metadata is split between the file header (for sequential file 
> information), and a combination of the file header and "within the 
> file" data for direct and indexed files.

Have a look at all the OpenVMS-isms in the file header, around—for 
instance—the nobackup setting, file protections and the ACL and its 
contents, the probably-too-limited FID, the file accessor mode, 
journaling, and file highwater marking—and ponder how that'll effect a 
port.  OpenVMS is quite fond of its metadata and apps have long become 
dependent on all of what's been exposed, and it's at the core of why 
OpenVMS has long had its own file systems.  VAFS was designed to 
provide much (all?) of what OpenVMS expects in a file system, which is 
why VSI selected it.   I don't know how extensible ZFS might be, in 
this regard.  Now as for what might be missing from VAFS as compared 
with the other high-performance and cluster-capable file systems 
around, we shall learn as details become available.  Details such as 
highwater marking and erase-on-delete just don't work how ODS-2 and 
ODS-5 file systems expected, too. Not on newer storage.


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