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Re: Formatting Hard-drives and Recovery

  • Subject: Re: Formatting Hard-drives and Recovery
  • From: Roy Schestowitz <newsgroups@schestowitz.com>
  • Date: Sun, 31 Jul 2005 06:36:04 +0100
  • Newsgroups: alt.os.linux.suse
  • Organization: schestowitz.com / Manchester University
  • References: <jn2hr2-j65.ln1@penne.houghi> <dc54ct$28ji$1@godfrey.mcc.ac.uk> <kvihr2-kf9.ln1@penne.houghi> <dc59s9$3lr$3@nntp.itservices.ubc.ca> <3kmvqjFug07oU2@individual.net> <HKGdnW5dbpV__HvfRVn-sw@rogers.com> <dc5oji$2eau$1@godfrey.mcc.ac.uk> <VqidnTx4IO-CNHvfRVn-1g@rogers.com> <dc6v0k$2on8$2@godfrey.mcc.ac.uk> <oY6dnQksYrWg8nrfRVn-2Q@rogers.com> <v08kr2-ckj.ln1@penne.houghi> <dc88tq$1914$1@godfrey.mcc.ac.uk> <slrndeit2c.6kt.ibuprofin@compton.phx.az.us> <dcc6ob$fg8$1@godfrey.mcc.ac.uk> <slrndeligt.abc.ibuprofin@compton.phx.az.us> <dcen3b$2bbn$1@godfrey.mcc.ac.uk> <slrndeofb5.dfk.ibuprofin@compton.phx.az.us>
  • Reply-to: newsgroups@schestowitz.com
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Moe Trin wrote:

> In the Usenet newsgroup alt.os.linux.suse, in article
> <dcen3b$2bbn$1@godfrey.mcc.ac.uk>, Roy Schestowitz wrote:
>>I have always believed that when formatting a floppy disk, going through
>>the sectors involved stuffing them with arbitrary bits or just zeros. I
>>could imagine that quicker forms of format were not a magic solution, but
>>all I had on floppies at the time were games, though rarely I had some
>>shareware, lightweight programs.
> Long before DOS, the normal preparation of magnetic media was to "zero"
> the data, as well as (perhaps) creating a file system (which most people
> call formatting). There is a good bit more to that, but the concept is
> correct.

I probably need to understand magnetic storage a little better. I have
always taken it for granted.

>>As for hard-drives, formatting time always appeared miraculously short,
>>which ought to imply that the process was rather shallow. I did not format
>>many hard-drives in my life though. I can recall the duration of one hour
>>or so, but I might be wrong. Maybe my memory betrays me.
> If your early memories are 'format /q', most of the hard drives used in
> computers by that time were already low level formatted out of the box,
> and all you needed to do was partition and (high level) format. The low
> level format procedure was a pain - requiring use of the DOS DEBUG
> command, or a floppy like the IBM Advanced Diagnostics for PCs. There is a
> SCSI command (FORMAT UNIT - op-code 0x04), but virtually all modern drives
> ignore the command today. Actually, the requirement to low level format
> a drive (other than the initial setup done by the manufacturer) has
> pretty much gone out the window.

This predates my days of computer use, I am fairly sure. However, I remember
being intorduced to a hard-drive in my friend's house (I think it was 40
MB). My first hard-drive was 170 MB in capacity.

> One major reason used to be the stepper
> motor drives (where the head positioner was a stepper motor) wear, causing
> the tracks to "move". All hard drives made today use some form of servo
> mechanism (either a dedicated servo surface, or a mechanism where the
> heads track the data). You can still see this problem on floppy drives
> which always used stepper motors. In early floppy drives, there used to
> be a mechanical alignment procedure, but improving manufacturing technique
> eliminated most of the need for this.

Just imagine that volumetic storage (Hitachi) is soon going to cope with
alignment in 3-D.

>>I still remember the days of undelete.exe and tools like Norton Disk
>>Doctor (along with other utilities from the prolific Norton).
> "UNDELETE.EXE" was from Central Point Software, and was licensed to MS
> and added to MS-DOS 5.0.  The Norton program was UNERASE, and predates
> both. I _think_ it was created in 1982, before the IBM PC-XT was out
> (meaning before most personal computers had a hard disk).  Norton Disk
> Doctor was a part of the Norton Utilities version 6 - prior to that, it
> was called 'NU' (nu.exe).

I can only recall nc.exe as well as ndd.exe, which I used several years
afterwards. I have always wondered why undelete.exe wanted the first letter
as user input, but realised and speculated this had a good motive. I think
that Windows 95 still had a front-end and filesystem support for undelete.
What now? Wastebasket? Third-party software with accompanying spyware? 

>>They were a true evidence for the fact that only file allocation tables
>>were affected in the interest of speed gains.
> This has always been a tradeoff. In the early days of the PC, (it was
> usually) game programmers would try to write directly to the hardware
> (usually the display adapter) to try to ring out that last bit of
> performance. After all, a 4.77 MHz 8088 was _slow_!!! But they weren't
> the only ones. Microsoft Word defaulted to saving the original document
> and the changes to it, rather than saving the changed document. Thus,
> you could see what the writer originally wrote (and then changed in later
> editing sessions) which sometimes could be quite embarrassing.

I doubt that many publishers dug up data from the hard-drive rather than
handling the raw output.

>>Sadly enough, there was never a way (a /common/ tool) of scrambling all
>>unused sectors on a drive.
> Norton's Wipefile and Wipedisk go back to about 1984, but there were some
> neat 'freeware' and 'shareware' utilities that were available.  Somewhere,
> I've got a file list...  Found it - 2882 programs totalling 120.4
> Megabytes that were available at a NASA BBS server. They in turn probably
> got the stuff from 'wsmr-simtel20.army.mil' (don't bother - that dinosaur
> was shut down in 1993, although you _MAY_ find mirrors at
> wuarchive.wustl.edu or oak.oakland.edu). You would have wanted a program
> like 'RZF.ZIP' (15360
> bytes) or 'PURGE.COM' (1536 bytes).  Just as a comparison, earlier this
> month, sunsite (now called ibiblio.org) had 656507 files totalling 49.107
> Gigabytes, and that doesn't even include the Linux distributions, which
> are on a separate server.

These are not so-called astronomical figures when compared with the Web
Archives (petabyte storage). My personal files on this computer are around
110,000 in number (~8 GB) and some of them are TAR or ZIP archives.

>>You must be a big storage expert
> No - a long time ago, in a land far, far, away, I did hardware support as
> part of my daily toil.  I'm actually a network admin.

Sounds like a much more appealing job to me...

All the best,


Roy S. Schestowitz

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