[time-nuts] OT: Disk Drive recovery.

[Markus Kern]

I haven't been following the recent disk drive thread but the
mention of grc.com on this list makes me cringe. Steve Gibson is the
kind of guy who has just enough knowledge about any given subject to
be dangerous. See for example [1] and specifically [2] in this case.

I have never used Spinrite but given Gibson's track record in computer
security I would never use any code he has written in an attempt to
recover data that is in the slightest important to me.

I won't claim that Spinrite doesn't occasionally recover some data
from a disk which has bad sectors but the fact that it writes data
right back to the same drive makes it much more dangerous than helpful.

Spinrite also gives a false sense of security in that people believe a
"repaired" drive can still be used. If a hard disk drive starts
causing read or write errors during normal operation it needs to be
replaced ASAP. Even if some tool appears to have repaired it, it can
no longer be trusted to safely store your data.


[1] http://www.radsoft.net/news/roundups/grc/
[2] http://www.radsoft.net/news/roundups/grc/20060123,00.shtml


-- 
Markus



On 07.12.2009, 12:24 Dave Baxter <dave at uk-ar.co.uk> wrote:


> For many "failed" hard drives, it's not a "hardware" failure at all, but
> a very corrupted data surface, rendering even the drives own error
> recovery useless, so the OS won't boot, or comes up in "an altered
> state" or similar woe.

> If the drive spin's up, and you can see it OK in the list of devices in
> the machines BIOS, it could be recoverable, with Spinrite from grc.com.
> No affiliations, other than a very satisfied user.

> Depending on the exact problem and the size of the drive, ammount of
> corruption etc, it can take minutes to days (weeks even) but if it is at
> all recoverable, it will get it back.   Often, you dont need to get the
> whole file back, as often it's the "slack space" that's bad, but it has
> to be read by the drive and OS anyway before it'll let you have your
> data!

> It's only the software tool that many so call hard drive speciliasts use
> first anyway.   Only if the drive does not show up correctly in the
> BIOS, or it can't spin up correctly, is it then a job for the clean room
> screwdriver types.  If it wont spin, or ID's wrong in the bios, you can
> try swapping the electronics board with another drive of the same
> make/model.  Often that will get you access to your data.

> However, be aware that hard drives themselves often "boot" from a
> special track (-1?) and if that gets corrupt, not even Spinrite will get
> it back, as the drive's own CPU and OS won't be behaving correctly! 

> Of course, depending on the ammount of work it has to do, and time
> taken, it would be wise to migrate the recovered data to a new drive
> (tested for defects with spinrite first of course.) 

> As earlier, I'm just a *Very* satisfied user of that software, having
> got me out of a hole several times with older hardware now.  With a bit
> of background informaion (I used to rebuild hard drives for a past job!)
> It's not free, but it's the mutt's nuts as it were.  If you use PC's for
> anything significant (regardless of the OS) you should in my mind have
> your own copy of this software.

> You can even recover PVR (Freview, Sky box etc) disks too, and those
> from iPods  ;-)   Once you've connected it to a PC somehow.   Even via a
> USB/IDE adapter!   Spinrite doesnt care what data or OS is on the drive
> needing work, it's a totaly self contained environment that itself boots
> from a CD or flopy.

> It works on floppies too, in fact any magnetic disk media.  DO NOT USE
> IT though on Flash memory, that can be permanently dammaged by repeat
> writes.

> I've used it to recover a PC that when booted was a Blue Screen problem,
> with errors relating to corrupted kernel files on the disk.  Everyone
> else (even the so called profesionals) said a new drive was needed, and
> reload the OS, loosing everything.  An overnight run of Spinrite later,
> and the machine booted with everything present just as of old.  The so
> called IT support co now have their own copy too!

> Even if you have good backups etc, after reloding an OS, the time taken
> to restore all the backups and application software is a major expence,
> and it never comes back that way 100% as it was.  (I've done it too many
> times!)

> Go to grc.com, and read about it.  Dont just take my word, see what many
> other people say about it.

> Regards.

> Dave G0WBX.