Re: [Bug-ddrescue] ddrescue produces 0 bytes output

[Jay Ashworth]

----- Original Message -----
> From: "Paul L Daniels" <address@hidden>

> Jay Ashworth <address@hidden> wrote:
> 
> > ----- Orig
> > Rogerio is going to hate us. :-)
> 
> Let the debating begin... :)

I like that attitude.

> > Don't *ever* try to do a drive recovery through a USB bridge: pull
> > the drive out of the housing and hook it directly to a SATA port. You
> > can't trust a random USB bridge chip to have enough commands to do
> > everything you need to do during a recovery.
> 
> What sort of commands? To date I've not had any problems with
> USB2 or USB3 external docking units. I have found no troubles
> that I'm acutely aware of with powered USB external-drive
> enclosures either (Seagate); sometimes I have had hiccups with
> 2.5" non-powered bridges, but that's somewhat to be expected
> due to the limited power, especially if the drive has a motor
> issue. Overall I have found recovery via USB-bridges to be
> more dependable than eSATA or SATA directly, particularly if
> the drive resets frequently. Though it's likely a
> kernel/driver issue I have found that when directly connected
> to the SATA interface I often have the drive become completely
> no-responsive to the system ( but reestablishes fine if you
> reboot ).

I am quoting others; I have never done a recovery attempt through
a USB bridge, based on their recommendations.  Alas, I'd have to go
dig you up references; I often store only the integrated result, 
rather than the source material, in my head.

> Different anecdotal evidence I suppose.

Probably, but their reasoning rang true for me.

> > I agree with cool, and you might find it worth freezing it, though
> > you need to put it in a ziploc and press all the air out beforehand
> > to avoid condensation.
> 
> No matter how much you press out, there's still enough moisture
> in the atmosphere contained in the drive that you'll get
> condensation on the actual platters when you pull it out of the
> freezer. If you must freeze a drive, then I suggest doing so in
> a very low humidity environment. I prefer to keep it between
> 5~10'C so as to avoid dropping below the dew point.

I've only had to do it once, and it helped, but only just enough.

If you ever have to do it, of course, you're trashing the drive immediately
after, but that's true of recoveries in general, so...

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       address@hidden
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates     http://baylink.pitas.com         2000 Land Rover DII
St Petersburg FL USA               #natog                      +1 727 647 1274