[Info-vax] ODS-5 data/file recovery

[Stephen Hoffman]

On 2013-02-16 14:41:06 +0000, Paul Sture said:

> That is going to be the tricky bit.  Did the File Systems Internals book
> cover ODS-5 or did it precede it?

Kirby's book was ODS-2 only, and it omits updates — many/most/all are 
common to both ODS-2 and ODS-5 — such as the GPT shuffle and the 
extended bitmap support.

In terms of what is on-disk, there's very little difference on-disk 
between ODS-2 and ODS-5.  Largely, FI2DEF versus FI5DEF, with the 
latter used for the ODS-5 filenames.  While FI2DEF versus FI5DEF is 
applicable to scrounging up old blocks, there's not a significant 
difference from the perspective of a tool that's scanning the headers 
and finding the filename among the detritus, and getting from there to 
any remaining extents.

The more significant changes in OpenVMS involved with implementing 
ODS-5 were in the XQP and RMS and the various utilities, with some 
changes in MOUNT and INITIALIZE and ANALYZE /DISK and some other 
places.  Of dealing with parsing the filenames, increasing buffers for 
longer filenames, replacing any old filename assumptions, hacking out 
old hackery, etc.


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