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From: mg32+@andrew.cmu.edu (Michael Ginsberg)
Newsgroups: comp.sys.ibm.pc
Subject: Re: backup programs, DMA speeds
Message-ID: <8Yym5V200WB58jE1Az@andrew.cmu.edu>
Date: 29 Aug 89 23:50:57 GMT
Organization: Class of '92, Carnegie Mellon, Pittsburgh, PA
Lines: 25

Just a note:  One reason why you'd want to turn off concurrent DMA (read:
the hard drive is being read while the floppy writes) is that, while real
IBM's and good clones have seven channels, all dependable, many clones have
only one, or seven with only one really being proven in.  I have seen many
people make incrementals daily and full backups weekly only to find all the
backups are sludge.  One thing I would suggest to everyone is to make a full
and an incremental backup, and then restore it (just like everyone should pull
the plug on a UPS before they assume it'll handle glitches as you write to the
hard drive... but that's another story).  Another thing, many people find that
the dma works at a slower speed... I had an AT clone that did perfect backups
at 8 mhz, but at 12 it failed miserably (of course never telling you that it
was dying).  Many backup programs (such as FastBack Plus, but I don't really
trust this program in general so...) will test your system for you, trying to
make backups and restore at various DMA speeds, and it then recommends to you
one of the speeds...

But after all this rambling, MAKE SURE you check to see that you can really
restore your backups before depending on them!

--Michael Ginsberg
Carnegie Mellon University, Pittsburgh, Pennsylvania, USA

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