[AccessD] OT: But only Partly

>In those days, disks on mainframes were removable from the drives
themselves which were about the size of a washing machine. The disk packs
were about the diameter of a LP record and the ones we used were about 8
inches tall.

Must have been one of the old IBM hard disk cabinets.  It had drawers that
you could pull out and then unlock and remove the disk packs.  Those were 80
mb packs if memory serves me.  Something like 8 platters, heads on each
side, hydraulically actuated heads.

In 1972/73 I was trained by the USN to fix that disk drive system.

John W. Colby
Colby Consulting
www.ColbyConsulting.com

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Gary Kjos
Sent: Wednesday, March 21, 2007 10:37 AM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] OT: But only Partly

Ouch. We used to do Disaster Recovery Firedrills back in my early mainframe
days when I was a computer operator. We had an arrangement with another
local company that had a similar hardware configuration to ours that we were
backup sites for each other. In those days, disks on mainframes were
removable from the drives themselves which were about the size of a washing
machine. The disk packs were about the diameter of a LP record and the ones
we used were about 8 inches tall.
We would take our disks or maybe it was just backup tapes over to this other
company and they would let us use their system over night and we would
attempt to run our orders and print the picking documents. Since the
hardware configuration was slightly different we had different execution job
control that referenced the hardware they had there. I was mostly just along
to carry stuff in the early days but later on I was called on to run the
stuff too. When fixed hard drives and online terminals came along in about
1980 that ceased to be an option anymore as we would have had to actually
overwrite their files on the disk or they would have needed enough empty
space for us to load our stuff on and as disk was failrly expensive in those
days that wasn't a viable option. So instead we concentrated on getting
better covereage from our hardware maintenance group. And we used our backup
tapes pretty often when stuff got corrupted and had daily, weekly and
monthly full backups for an entire year of generations, so we were really
quite secure and fully tested backup wise. Noplace I have worked since has
had anywhere near that level of backup. But hardware failed a lot more then
than it does now too, so we get lulled into a sense of security that drives
don't fail. But in this case it wasn't even a drive failure that caused it,
it was a human mistake.

We had an occurance of the "can't read the backups" here a while back.
It was a very bad thing. There had been a change to the backup software
itself and maybe the hardware too. I don't remember exactly what the end
result was as far as data loss - don't think we lost anything - but we were
down for an entire day - no sales entered.
Order takers had to write orders down on paper to be entered later. I think
our website still took orders as it's seperate but there were no
confirmations etc. It wasn't a total loss as some of that business came to
us in the following days, but some of those orders went to other sellers
instead of us and perhaps some of those customers went away disgruntled too.

GK