fP and data integrity...how to maintain on non-quiescent systems?

[Fairlight]

Okay, scenario:

Company X is a 24/7 business running fP.

Let's assume about 80 tables or so.  Figure about 10 indexes on average.

Data goes back, say, 9 years or so, no archiving has been done, which fact
exacerbates a problem that creeps up even if the data was kept lean.

Now, let's assume they want backups.  Tape, rsync to another system,
whatever.

"table_A" is about 30 tables in sequential directory-traversal order from
"table_Q", and comes first in traversal order.

"table_A" is the detail file for the header information in "table_Q".

Let's nevermind that, in theory (actually, probably in practise), you could
get indices and a key that are mismatched while backing up just "table_A".
Let's just assume that's pretty rare, although I feel it's a bad
assumption.

Let's look at the time it takes (figure about 20-30min) to rsync or
tape-backup all the data between tables A and Q.  In that time, both tables
may have been updated, but the detail for things that got backed up in the
headers will be missing in your backup.

This leaves you with a non-viable backup.

Okay, some of you folks have been doing fP for 25 years now.  How do you
handle this kind of situation?  Generally speaking, backups should be run
when a system is quiescent.  I know with absolutely certainty that there
are businesses out there using it that are 24/7 and never have sufficient
inactivity to avoid this kind of issue.

I'm very interested in how anyone avoids this on an rsync.  For that
matter, rsync aside, how do you avoid it even with Edge, tar, cpio, or
anything else?  I'm coming up blank right now, so I ask--how does one
avoid this kind of problem?  This kind of thing would make even the best
bit-level verified tape/disk/whatever backup almost useless in many, many
circumstances.  I can just see a freight system with a tracking number and
scant partial data in the header record, but all of the supplemental data
gone missing.  NOT a good scenario.

Interested in hearing feedback on how to avoid/defeat this problem.

mark->
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