[Oberon] Strange Oberon users ?

[Bill Hacker]

easlab at absamail.co.za wrote:

> Imagine coming across a society whos members never use
> facilities which you find essential for life, yet who seem
> to cope perfectly well.   Like shoes or 'artificial heat'.
> 
> How do they prepare their food without 'artificial heat' ?
> 

? Scrape off the fish scales, slice neatly, mix a bit of Wasabi with Soy 
sauce...

> Here's another screaming example for the need for a
> date-ordered directory listing:
> the file-backup method of 'cycling through 3 media'
>  A,B,C, ie. the old data is just left [as a backup] when
>  the new data is copied from B to C, seems simple and 
> effective.

While files are 'shown' to you as if all-of-a-piece and arranged 
tree-fashion, neither has been true on storage devices since paper tape 
and punched cards passed from common use (if then).

> 
> With many partitions, the probability of an eventual
> break in the link of logical partitions becomes significant.
> [safety/redundancy in the links is also interesting]

It *might* be possible to find an EDM/2 series of articles on the IBM/MS 
'hpfs-386' files system, which is incredibly robust w/r data recovery, 
as well as resistance to loss in the first place.  Fast, too.  Really 
fast.  Worth a read.

hpfs keeps enough link information that it's 'chkdsk' , when run 'n' 
successive passes, can recover (much/most/sometimes all) prior data. 
many 'time' layers deep.  An archological fs, so to speak.

It *has* to, partly because it is constantly moving data around in the 
background - files you are not even using - in order to optimize storage 
to the media layout and the system's *current* usage pattern. Tries to 
minimize head-positioner movement, IOW.

But there is a price - and one that becomes unacceptable, 'Real Soon Now'.

Once the media size goes over 1 GB, chkdsk'ing a volume marked 'dirty' 
gets really slow, and one may brew, and drink, a cup of coffee while 
waiting.  And that is for a 'light once over' - not a recovery job.

With a 4GB partition, one can brew, and drink, your own beer.
And 100 GB?  One can lay up malt whiskey and age it....

Hence the appearance of JFS-2 (just called JFS on OS/2).
One of many available 'journaling' file systems these days.

BUT - there, too lies a caveat:  Journaling file systems recover 
rapidly, as they make the assumption that any file touched recently is 
in their journal, and all others were safely left dormant.

If/as/when that last assumption is not true, the rapid recovery of many 
journaling systems falls down.
Some are *more* difficult to restore when serious stuff goes awry.

> 
> When uncertainty of which of 2 or 3 partitions is the oldest,
> even if the partition are from different MOBOs [computers]
> and date-stamped by different clocks, the ability to just 
> consider the newest files [since the latest backup] would be 
> most valuable.

Flags to things such as 'DIR' or 'ls' will happily display newest-first, 
use modification date, or even access dates rather than creation dates, etc.

None of the above is much help if the media has gone pear-shaped...

There one needs backups on other media.  And utilities such as 'rsync' 
are able to transfer only what is new...

Noting you do w/r 'generations' or partitions on the same spindle is 
going to survive a bearing or head failure.

> 
> If a System.Directory <Partn>:*\d
>   could be date-ordered, one could merely compare
> the newest files of the 2 partitions - perhaps 2 %.

See above.  True 'date ordering' as opposed to date-ordered indexing 
and/or date-ordered display, puts a lot of restrictions on efficient use 
of a random-access, block-mode device (rotating memory in general, but 
flash and RAM such as well).

Mag tape, OTOH, would do just fine, *IF* you only ever wrote serially & 
sequentially to it.

IIRC, (and it has been a while...) even IBM TOS (Tape Operating System) 
was NOT restricted to sequential operation... so..
... paper tape, then.  The original 'Write-Once, Read Mostly' media. 
Cards won't do.  They get out-of-order when one drops the box..  ;-)

> 
> Doesn't any body else need such facilities, or is there a secret 
> re. not having to cook the potatoes which I don't know about ?
> 
> == Chris Glur.
> 

ACK.  Eating salads, sushi, and taking one's potatoes pre-cooked by 
others ;-)
(raw potatoes are edible, but can harbor nematode worms...)

.. so one can concentrate on stuff that DOESN'T yet 'work well enough'...

'Priorities', IOW.

Have a look at the DragonFlyBSD project.
Some marvelous ideas w/r really deep on-the-fly file archiving, even 
'playback' capability.

But if too much in the way of resources goes into an area that has been 
solved 'well enough' by any of several other means....
- it won't even be utilized...  Just as few of us back up files even 
when we have the space...

(I do use RAID1, though...)

Even the human brain  - on a daily basis - summarizes, compresses, and 
*discards* old and no-longer-useful data.

or at least posts it to a mailing list...   ;-)

Best,

Bill Hacker