[Info-vax] Re; Spiralog, RMS Journaling (was Re: FREESPADRIFT)

[Stephen Hoffman]

On 2016-06-18 08:54:54 +0000, Paul Sture said:

> cf VMS only storing the block sizes of files rather than the number of 
> bytes; this can be problematic for utilities ported from a system which 
> has an easy/cheap way to supply the exact size in bytes.

See the XAB$W_FFB first free byte value, for those file formats that 
aren't block-storage-oriented.

With OpenVMS, there's also the fairly user-visible distinctions among 
the file user content size in bytes, the file storage being used for 
the user data in blocks/sectors, and the total storage allocated to the 
file in blocks/sectors due to pre-extending and the rounding up 
inherent in the cluster factor.  Then there's the metadata embedded in 
various of the common formats, even within the various sequential 
formats.   Unix doesn't default to anything like VFC sequential files, 
after all.   Do you count that metadata in the file size, or not?  
Arguably no, but it's inherently part of the file on OpenVMS and not at 
all easy to exclude — whether VFC or the indexed file structures or 
otherwise.

Not that OpenVMS APIs and the OpenVMS docs even particularly lend 
themselves to presenting this or related information, either.   Having 
some decently-designed OO methods for retrieving this and other 
metadata would changes this into something rather easier to deal with; 
less glue code than is involved dredging through XABs.




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