Re: [tlug] Program to Save / Remap Bad Sectors

[CL <az.4tlug@example.com>]

On 07/13/2015 04:24 PM, Stephen J. Turnbull wrote:
> Just to confirm, you need to read it from Windows?  Otherwise, life
> will be easier if you reformat the disk to anything Linux likes
> (AFAIK, Linux still does not like NTFS very much).

No.  Not at all.  No Windows have been opened or closed in the creation 
of this problem.  (As opposed to another problem you knew me to be 
working on in which the installer for the program you recommended 
explicitly blacklists a key piece of my hardware and the .iso patch 
installer only runs on Windows PowerShell 4 .... *sniff*).

The disk in question is the oldest of several internal SATA disks (and 
half a dozen external USB disks) on a Lubuntu-powered entertainment 
box.  NTFS is sort of the standard for storing torrent files.  USB disks 
come formatted FAT32, which is okay for .avi (480p), but can't handle 
.mkv and other 720p / 1080p formats, hence the NTFS.  Ext 3~4 didn't 
improve performance enough to be a worthwhile re-format at the time and 
didn't work well on the USB externals.  IIRC, it also messed up smooth 
VLC playback (which is now reported to be fixed).

> However, there is this project:
>
> http://www.tuxera.com/community/open-source-ntfs-3g/
>
> The ntfsclone utility (not documented online as far as I found, I took
> a look at some of the manpage sources in the distribution tarball)
> seems to be the ticket.  Use the -rescue option.

I'll take a look but it appears that this disk may have gone to hardware 
heaven before its contents could be saved.  However, it is in a 
non-airconditioned room so I'll wait for it, and the box, to cool before 
entering funeral mode.  Refrigerating it for an hour helped the machine 
see the MBR, again, so I'll try that again before throwing in the towel.

> Bad sectors on read, I hope.  (Well, sort of.)  If you're seeing bad
> sectors on write, you really should exchange the disk while it's still
> in warrantee....

Bad sector errors on read.  George Bush was still president when this 
HDD was in warrantee, I think.  And, the brand is now owned by a 
different company.

> If you were copying to a Linux filesystem instead of NT, I'd say use
> dd with the conv=noerror,sync options.  [This appears to be equivalent
> to the ntfsclone -rescue command recommended above.)

Just about everything I'd been able to find said that ntfs was workable 
with Debian O/Ses so I have stayed away from NT options. I'll see what 
trouble I can get into with this information only if necessary.

> It's not possible to "fix" or "move" a bad sector that is causing read
> errors.  What can be done is (maybe) to read part of the sector[1], to
> write that data to a different sector, and to update the file metadata
> to point to the new sector rather than the old one.

I'm very aware of that.  I was using shorthand.  Maybe too short.

I also apologize if people thought that my mention of things that worked 
in DOS meant that I was looking for a DOS-based solution.  I wasn't.  
Thanks to everyone for the suggestions.  I have ddrescue and ddrescuelog 
installed.  If I can resuscitate the drive long enough to mount in 
Lubuntu one more time, I will be trying them first.

--
CL