-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Randall R Schulz wrote: > Hi, > > This is a follow-up to the thread "Hard Disk Failing." > > To recap, SMART reported drive errors of the "...XYZ..." variety on a > young and lightly used Western Digital Raptor drive. > > It turned out (see below) that any attempt to access any of sectors > 261200 through 261343 (a 144-sector range) would trigger retries that > ultimately failed. SMART self-tests likewise failed upon reaching the > first of these sectors. > > Reading some articles on SMART by Bruce Allen (the author of the > smartmontools package) suggested that these errors can sometimes be > caused by mere discrepancy between the ECC data and the 512 bytes of > actual recorded content of a given sector and that there could be many > causes for this, including power failures while writing. > > I decided to try a simple experiment: I would determine all the sectors > that elicited an error when they were read and then rewrite them. I did > this by using the "dd_rescue" utility. One of its options (-o) records > a list of blocks for which unrecoverable errors were reported by the > OS. This is how I obtained the list of 144 sectors that showed read > errors. > > Note: dd_rescue is apparently not designed to write to /dev/null, and > every write operation it attempts to /dev/null yields an error message. > > Once I had the list of (supposedly) bad blocks, I simply used an > invocation of "dd" (the stock dd, not dd_rescue) to copy zero bytes > (supplied by /dev/zero, of course) over the failing sectors. > > Voila! After this, the bad sectors could be read without eliciting any > error indication at all, requiring no retries nor producing any kernel > messages. > > > The moral: Don't give up easily if you have a young, expensive drive > that starts to give you SMART errors! > > > An interesting aside: The actual capacity of this drive appears to be > nearly 7 GB (out of just under 140 GB) _larger_ than specified. > > > Randall Schulz
This and the other posts are very useful ... something for the atchive,, thx - -- ============================================================================== I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone. Bjarne Stroustrup ============================================================================== -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFHNYYBasN0sSnLmgIRAlbfAJ9aLvCjOw7mB7gqp0lo6i0O8kzcbwCg+QIx Y8IbrplARDUaYd8RzOFjw/8= =kCFP -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
