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From: baron@transys.UUCP (Joe Portman)
Newsgroups: comp.unix.wizards
Subject: Re: On backups
Message-ID: <332@transys.UUCP>
Date: Wed, 20-May-87 16:19:42 EDT
Article-I.D.: transys.332
Posted: Wed May 20 16:19:42 1987
Date-Received: Sat, 23-May-87 09:17:41 EDT
References: <7272@brl-adm.ARPA> <2651@cit-vax.Caltech.Edu>
Reply-To: baron@transys.UUCP (Joe Portman)
Organization: TransSystems Inc. Bellevue, WA
Lines: 26
Summary: Did'nt they ever hear of rotating backups

In article <2651@cit-vax.Caltech.Edu> mangler@cit-vax.Caltech.Edu (System Mangler) writes:

>Some consultants here did their backups by periodically copying the
>active disk pack to a backup pack.  One night, the active pack crashed
>in the middle of a backup.  They were left with half of an image copy
>of the filesystem, which is completely useless; they lost the entire
>sources and compilers for their proprietary operating system.  A year
>later, they are still stuck with making binary patches.
>So it doesn't require two simultaneous head crashes to lose a lot.


	Yup, what about fires, vandalism, burglary, etc... These are all
	very real considerations. On all of our machines we use three sets
	of backup media in rotation. One set is always kept off-site in a
	fireproof vault, and a master gen set is kept at the company presidents
	home, updated about once a month. This may not be feasible for very
	large installations, but the principle applies: Spread out your 
	area of risk.
	
	Too much trouble, too expensive, you say, well we have had a few
	disasters here, fried disk drives, etc... All of which were fairly
	easily recovered, because fairly fresh backups are always available.

	As the saying goes, "YOU CAN'T HAVE TOO MUCH BACKUP".
	
	Just my .02 worth.