Re: APYJRNCHG

["R. Bruce Hoffman, Jr." <rbruceh@xxxxxxxxxxxxx>]

-----Original Message-----
From: Jim.Nelson@RCIS-NET.COM <Jim.Nelson@RCIS-NET.COM>
To: midrange-l@midrange.com <midrange-l@midrange.com>
Date: Wednesday, August 22, 2001 10:17 AM
Subject: RE: APYJRNCHG


>
>Just to be sure, has anybody actually recovered a journalled file saved
with
>SAVCHGOBJ and OBJJRN(*YES)?
>


Recovery - Yes, long ago and far away, disk drive failure on early 400,
total system loss, receivers on tape. To be fair, the recovery of data from
saves and receivers took only 1/2 day. The office documents, the disk drive
itself (physically, had to come from Scotland) and some tape issues took the
better part of 3 days.

But most of my more recent use has been during resync on CISC to RISC.

Geez. I never answered the original question....

TIme. Restore of all objects takes t amount of time. Restore of all saved
objects takes t/o time where o is the some size and number of objects saved.
Roughly a percentage of the volume saved. If you have 30G of data in one
file and the rest of the system is 10G and that 30G file changes every day,
the roughly 80% of the full restore is going to be needed again to restore
the changed object. If you have journal changes, it's the number of changes,
and that depends on so many variables. CPU capability, mirror vs raid, dasd
controllers, number of arms... blah, blah, blah.

The only sure way is to try it. Restricted state or new machine. Full backup
of the file in question. Restore the file from a prior save under
journalling. Apply the journal changes to current. See how long it takes.
Full restore of the file from this full backup. Would be same as restoring
file from save changed. Which one takes longer? What's the rate of journal
changes applied?

Now you can truely estimate the times for your situation, and _really_, your
mileage WILL vary from every one else's.


===========================================================
R. Bruce Hoffman, Jr.
 -- IBM Certified Specialist - AS/400 Administrator
 -- IBM Certified Specialist - RPG IV Developer

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