[sf-lug] semi-OT: help with dying disk

[Asheesh Laroia]

On Thu, 13 Mar 2008, matt.price at utoronto.ca wrote:

> hi folks,
>
> i htink i may have asked a similar question before, since this is the
> second time in 3 months that i've had a disk drive die, and no, i
> apparently still haven't learned my lesson.

I'm in a bit of a rush, but data disasters call for immediate action.

You should install the program called "GNU dd rescue", available in Ubuntu 
(and therefore on the Live CDs, if you enable the Universe repository) as 
the "gddrescue" package.

Then you should use gddrescue to back up the raw partitions you care about 
to a file on your new disk:

$ sudo ddrescue  /dev/disk_partition /destination_drive/image.img /destination_drive/image.log

Once you get bad sectors on a disk, you should avoid writing to it if 
possible - do your recovery on a disk *image* - doing otherwise is like 
trying to redecorate the kitchen table on a sinking ship.

People may talk about dd_rhelp and another program called ddrescue or 
dd_rescue by Kurt Garloff, but in my opinion GNU ddrescue is strictly 
better.

Run your fsck on the image.  /me dashes out the door

> then i have a second one, regarding a new disk.  from the looks of it,
> $150 will now buy either 200 gigs of 7200 RPM  2.5" disk, or 250 gigs
> of 5400 RPM.  any idea how the speed difference is likely to affect
> both speed and power consumption on my laptop?  this is a dell d820
> laptop with a core duo cpu, so it's fairly quick by my standards, but
> of course i wouldn't mind it being faster; however, it's also a
> terrible power hog under linux, currently (with what i believe is a
> 5400 rpm disk) barely staying up for an hour on battery power.

Less than hour is not really normal on any modern laptop, I think.  Have 
you checked if the battery is in as good shape as it was originally?  Try 
poking around cat /proc/acpi/battery/ , especially cat 
/proc/acpi/battery/*/info .

Also look into lesswatts.org for lots of tech details that even I haven't 
gotten into yet for how to optimize power usage.

> so i wondered, any comments on the likely speed/power tradeoff, and
> also any hints about increasing disk lifetime?  this is the first
> laptop drive that's failedo n me, and i'm wondering whether it's just
> bad luck, a bad manufacturer, or possibly some defect in the way that
> disk access is managed under recent versions of ubuntu.

I'm pretty sure it's just bad luck.  It happens to all of us after a 
while.

Run, don't walk, to GNU ddrescue.  If you need somewhere to store your 
drive's contents temporarily, feel free to give my cell phone a call (you 
can find the number at e.g. 
http://www.google.com/search?hl=en&q=call+%22asheesh%22 ).  I can make 
space.

-- Asheesh.

-- 
As you will see, I told them, in no uncertain terms, to see Figure one.
 		-- Dave "First Strike" Pare