[comp.sys.next] backup to the floppies

chin@sg1.chem.upenn.edu (Chin Wu) (01/26/91)

Hi,
    I am trying to backup the 105Mb hard disk to floppies, but I have
some problem restoring the files. Following Mr. Lawrence Clarke's
advice, I format 90 1.44Mb diskettes, log in as single user, then
issue the dump command:

> dump 0uOf 0.82 /dev/rfd0a /dev/rsd0a

where 0.86 in the original post doesn't work. And 0.82 is the
highest value which will cause the smallest number of diskettes used
in the dump process.

Anyway, after dumping all the files to the diskettes, I want to
restore some files to make sure that it is a two-way process with no
avail. I have used:
> restore jif /dev/rfd0a
and
> restore if /dev/rfd0a
as suggested in Mr. Lawrence Clarke's post.

Has anyone done this? And how does people own 2.0 Extended release
restore the files to the hard disk?
--
chin@sg1.chem.upenn.edu

uskmg@mathcs.emory.edu (Ken Guyton {EUCC}) (01/29/91)

While trying to do an incremental dump to HD floppies with the command...

     # dump 5uOf 1.22 /dev/rfd0a /dev/rsd0a

...I consistently received the following error on the second disk...

DUMP: DISK write error 1472 disk blocks into disk 2.

I reformatted disks, tried three different disks, and even tried the
dump by using the disk that had been working as #1 as the #2 disk.
The other disk that had been failing worked fine as #1 and the disk
that *had* been working as #1 failed as all of the others.  The bottom
line is that the error seemed to be independant of the disk that was
used.

Before this I had successfully done the same kind of dump to three
floppies.  I finally dumped to an OD (on another machine across the
net) and have not tried a floppy dump since then so I don't know
whether this is something peculiar to this particular dump.

Does anyone have any ideas or clues?

Thank you.




-- 
Ken Guyton          | uskmg@unix.cc.emory.edu          PREFERRED
Emory University    | ...gatech!emoryu1!uskmg          UUCP 
Academic Computing  | uskmg@emoryu1 OR uskmg@emuvm1    NON-DOMAIN BITNET  
Atlanta, GA  30322  | Phone: (404) 727-7685

Phil_AZX_White@cup.portal.com (01/30/91)

Someone mentioned they had read somewhere that DoubSided?DoubleDensity (Dfl

Phil_AZX_White@cup.portal.com (01/30/91)

Someone told they had read an article stating that
Double Sided Double Density (DSDD) 800K floppies could be
made to work like High Density (DSHD) 1.44MB floppies by
punching an appropriate hole in the casing.  Didn't seem
to me like a good idea, but if it works (as the article claimed),
than sounds like a money saving approach.  Has anyone heard
of this?  Would assume the same procedure could be used
for the ED 2.88MB floppies.  I would think limitations 
of the magnetic media would make this approach risky.

Phil

scott@texnext.gac.edu (Scott Hess) (01/31/91)

In article <38639@cup.portal.com> Phil_AZX_White@cup.portal.com writes:
   Someone told they had read an article stating that
   Double Sided Double Density (DSDD) 800K floppies could be
   made to work like High Density (DSHD) 1.44MB floppies by
   punching an appropriate hole in the casing.  Didn't seem
   to me like a good idea, but if it works (as the article claimed),
   than sounds like a money saving approach.  Has anyone heard
   of this?  Would assume the same procedure could be used
   for the ED 2.88MB floppies.  I would think limitations 
   of the magnetic media would make this approach risky.

First:  This is dangerous.  Only use it on your borderline
data (games come to mind).  Even though most disks will
work, there are bound to be a number that won't - what
is the $20 saved when you lose that term paper?

This probably won't work for upping 1.44M to 2.88M, the
reason being that the 2.88M disks are supposed to use a finer
media with a different base (or something on that order).
I _certainly_ wouldn't try it with a 720k floppy, if I were
you.
--
scott hess                      scott@gac.edu
Independent NeXT Developer	GAC Undergrad
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