• Subject: Re: Signing -off for Daily Back-ups
  • From: MacWheel99@xxxxxxx
  • Date: Wed, 4 Apr 2001 03:23:00 EDT

From Alister Wm. Macintyre

Please excuse my geography question - I am not trying to be insulting :)
I am not totally ignorant about India, even before reading
http://www.yourdon.com/tyr/issues/Vol02/0202.html

Is India a nation that spans the world or do you have night time like 
everyone else where there is very low usage?  If the ATMs go down at 3 am for 
backup, who is going to notice?

Do you operate your factories for 24 hours a day 7 days a week?  Or do you 
have a time period in the course of the 24 hours or 7 days in which the 
volume of users is significantly diminished.  That is the time to be running 
your backup.  

Actually the way BPCS is structured, you have to kick people off the system 
for more than backup reasons, so it is possible that if you are not involved 
in this side of the operations, someone is fibbing to you ... it is much 
simpler to tell the staff "You need to get off the system for 2 hours so we 
can do backup." than to tell you the truth about reorgs & rollups.

I use ATMs that sometimes go down - I sometimes read the error messages on 
the screen trying to figure out what kind of computer system they must have, 
out of curiosity.  Except when it is pretty obvious from the error messages 
that the entire bank is down, the ATMs tend to lie to us the same way that 
the Airline industry lies to us when things do not go as advertised.

Since you are new to ATMs, it is possible that the India banking industry is 
copying the sins of the parts of the world that have had ATMs much longer.  
For an inside track on many ways the banking industry can seriously mess up 
your life, check out.
http://www.egroups.com/files/e-com-sec/electronic+commerce.htm

If you have a hard time connecting, I can e-mail this e-fraud report as an 
e-mail attachment ... it basically explains how identity theft is an artifact 
of incompetent banking practices & a whole bunch of other inside stories from 
the dark side of the financial industry.

If you have plenty of disk space it is not neccessary to kick people off 
AS/400 to do backup.  My explanation is simplified because you are just an 
ordinary BPCS user so I do not need to dress it up in technical detail.

IBM has something called "Check Pointing" in which it marks various files as 
"This is the reality at say 7 pm." then it starts the backup, which will run 
for a couple hours, WHILE PEOPLE ARE STILL USING THE SYSTEM but what is being 
backed up is a replica of what the files were as of the 7 pm reality, not how 
they are at the moment some file is copied to tape, which means that there 
has to be enough disk space to keep track of the 7 pm story & the story since 
7 pm, and tell the difference. 

Depending on how busy the system is & how long the backup is, the 400 is in 
effect keeping duplicate copies of many file records ... the copy as of 7 pm 
until the backup gets done & the copy since 7 pm ... then when the backup is 
done, it has to wipe out the 7 pm copy & replace it with the since copy.

HOW DOES IT DO THAT?

Well there is something called journaling, which is in essence keeping a log 
of all the changes to the files, with delayed update until after the backup 
is completed, but the users accessing changed stuff might be slower because 
they getting a temporary copy of 7 pm plus the journal, except it does not 
have to be slower if the company buys the extra hardware to get good 
performance..

Most places use journaling for an entirely different purpose, so we tend to 
forget about this application. 

There are variations on this, but at many firms they do not want to buy the 
extra disk space for RAID or mirroring or journaling or check pointing.  It 
is simpler to buy a smaller system & kick everyone off for a couple hours per 
backup.

Do you have a PC which you backup?
There is a common practice on some PCs to do something, which is also 
supported on the 400.
Over the weekend you backup everything.
Monday nite you backup ONLY that which changed on Monday.
Tuesday nite you backup ONLY that which changed since ....

well there are a number of ways of doing it, but given the way BPCS has 
members & logicals intertwined, it can be a royal nightmare reconstructing 
this if you have to restore the weekend tape, then the Monday tape, then the 
...

You might also check out the state-of-art of DATA COLLECTION.

I am summarizing here to paint a big picture, since you are not a technical 
person.

You have PCs out on the shop floor.
Previously you have downloaded to them copies of key 400 files associated 
with shop orders.
People enter the shop floor reporting data to the PCs using bar coded wands & 
other stuff so as to dramatically reduce error rates & human hassles.
For example, the computer has a whole bunch of information that you should 
not have to key in, like it KNOWS today's date & if you enter the order & 
operation it can look up work center & loading code so you not have to enter 
if this is machine or human & if the labor ticket was bar coded in the first 
place you not have to key that in.
The PCs use their downloaded shop order files to verify the data when the 400 
is not available.  Like is this a valid quantity to be reporting, and is this 
a valid crew number.
When the 400 gets done with the backup, you run the job to upload from PCs to 
400 the data associated with shop floor reporting that was going on during 
the backup, and then the PCs get updated copies of the shop floor files.
Actually right before the backup, the 400 story gets refreshed to the PCs.

Not all Data Collection software packages are this sophisticated.

Bottom Line ... your implementation team needs to check out the SIZING 
QUESTIONAIRRE in which SOMEONE at your company DECIDED that you are going to 
shut down access to the system for 2 hours each night for backup, or however 
long it is going to take, instead of buying the hardware resources so that 
would not be neccessary, or someone is RESPONSIBLE for this decision without 
really understanding all the implications & perhaps this is worth auditing to 
make sure that what you are asking about is REALLY what they want to do.

I am sure IBM rebranding has a new URL but this might help you locate the 
thing
http://www.as400.ibm.com/configure/Welcome.htm

Al Barsa's site had one once ... you can get to it from midrange dot com then 
midrange resources

Basically the SIZING QUESTIONAIRRE talks about what YOU NEED
then this translates into how much hardware to accomplish that.

What often happens is that a company figures out what they REALLY NEED
then when they see the price of the hardware there is STICKER SHOCK
and they scale back what they will settle for

What the state of art needs I think is a SIZING SIMULATOR
It would start with what you now have or are getting

You would say WHAT WOULD IT COST to not have to kick everyone off the system 
for 2 hours for backups & then some management level reconsiders whether that 
cost is justifiable.

>  From:    Bharat.Balsavar@IN.nestle.com (Balsavar,Bharat,MOGA,ISD)
>  
>  Hi All,
>  
>  I'm not a computer/software specialist. Only a user of BPCS.
>  
>  I've often wondered why the ATMs installed by banks do not stop for 
allowing
>  daily back ups of the banks' servers. Or, does the daily back-up happen at 
a
>  time when any customer is least likely to use an ATM?
>  
>  I've been using ATMs for almost four years now - they're relatively a new
>  thing in India's developing economy - and never ever seen any 'Please Wait.
>  Daily Back-up in Progress' or 'Account presently not accessible due to
>  back-up' display on the screens.
>  
>  AS/400s, I believe, are the mainstay of most banks. If so, why do we BPCS
>  users have to sign-off for a set period every night for taking back-ups and
>  not the ATM users?
>  
>  Isn't there some way that on-line entries on shop-floors be continued while
>  the back-up goes on? The entries keyed in during back-up time can be stored
>  in/as temporary files and be updated in the system once the back-up is 
over.
>  Is such a thing possible?
>  
>  Any comments please.
>  
>  ---
>  Bharat D Balsavar, BPCS Implementation Support Team
>  Moga Factory - Nestlé India Limited

MacWheel99@aol.com (Alister Wm Macintyre) (Al Mac)
AS/400 Data Manager & Programmer for BPCS 405 CD Rel-02 mixed mode (twinax 
interactive & batch) @ http://www.cen-elec.com Central Industries of 
Indiana--->Quality manufacturer of wire harnesses and electrical 
sub-assemblies - fax # 812-424-6838

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