low-level formatter for linux

[Bill Davidsen]

Tony Nelson wrote:
> On 09-08-08 11:54:37, Bill Davidsen wrote:
>  ...
>> I'm not sure what you expect low level formatting to do for you,
>> backing up and writing and reading to every sector will force all 
>> current bad blocks to be found, 
> 
> One thing is that each of those blocks requires a long seek to the 
> replacement block.  After the drive manufacturer's low-level format, 
> all the blocks are in order, with only short skips past the bad blocks, 
> and possibly a slight reduction in the size of the spare blocks area.
> 
> 
>> but honestly "has developed many bad blocks" is another way of saying 
>> "is failing" and is a hint to replace now. When a drive starts 
>> relocating sectors (as seen in SMART), something is wrong with the 
>> drive. ...
>  ...
> 
> Modern drives (last 8 or so years) have good support for automatic 
> remapping of bad blocks, because bad blocks are expected at the 
> magnetic domain sizes being used.  With Automatic Offline Testing 
> enabled, most bad blocks are remapped before complete failure and 
> without data loss.
> 
> I've been using one "dying" drive for 7 more years now (with one low-
> level format), and another for about 4 more years.  I'm using a drive
> I found in a snowbank, without difficulty and without bad sectors.  I 
> have SMART monitoring enabled, so email will be sent to root if SMART 
> gets unhappy, and Auto Offline Data Collection enabled, so blocks are  
> being salvaged as they go bad.  I'm /not/ using that panicky Palimpsest 
> (gnome-disk-utility applet), so I don't get spurious warnings (moderate 
> numbers of reallocated sectors are not bad -- though offline-
> uncorrectable and pending sectors are bad).
> 
Depends on your ratio of time to money. I just bought a 500GB WD "green" drive 
for about $55, I don't have to spend time fiddling with backups (not to mention 
trusting them) other than the regular, and I can do each of the steps to clone 
and verify, including the drive swaps, in time increments shorter than a 
commercial break or a kernel compile. So I can watch a game or race with my wife 
or while something downloads, or compiles, or I'm on hold with vendor support, 
and I value my time a lot more than $55. Actually if I save billable time I make 
money, but that's a different issue.

If you like to fiddle with computer hardware, or are on a tight budget, getting 
the last rotation out of the drive makes sense. I regularly give my old drives 
to my assorted relatives because replace or upgrade makes sense to me. I have an 
obsolete machine with DBAN as the OS.  ;-)

-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot