[ale] possible to use hard drives that have bad blocks ?

John Mills johnmills at speakeasy.net
Sat Jun 25 14:02:51 EDT 2005


Courtney -

I'm not sure if the error message implies an localized fault, but I have 
had some success avoiding reuse of bad disk blocks.

See 'man badblocks' - you can mark unusable blocks in the partition's 
table and they should thereafter be avoided. I have done this on ext2 
filesystems, though not recently. Note there is a recommendation to invoke 
'badblocks' through 'fsck' or 'mkfs' to ensure a match of block numbers 
with your drive's physical geometry.

In at least one case I knew the problem blocks as a result of failed 
backup copies, and could identify them with specific files. I deleted the 
files and was able to add those blocks to the partition's list without 
rebuilding the filesystem nor losing other data. YMMV, naturally!

Best of luck.

 - Mills


On Sat, 25 Jun 2005, Courtney Thomas wrote:

> I've got a couple of HDs that when I:

> dd if=/dev/hdX of=/dev/null bs=1m
 
> I get a single instance of something like:
 > FAILURE - READ_DMA status=51 <READY, DSC, ERROR> error=40
 > <UNCORRECTABLE> LBA=19194112 Input/output error
 
> My question is: does this signify a single bad block and is there a way
> to identify this error to some program that can block it's use, so the
> drive can be used ?



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