What badblocks does and doesn't do, for those interested.
I ran
nice badblocks -b 512 -c 8192 -t random -n -p 5 -s -o
on a disk area I knew to be dodgy.
Around the bad sectors, the disk makes some clicky noises, and each
time the kernel decides to give up and disable DMA. Result: "Your mouse
has moved. Please wait for your mouse pointer to update". Typing any
text at normal speed leads to random characters, one has to type the
"hdparm -d1 /dev/hda" one character per second. (That much Sascha for
running with DMA off...) I stick with my opinion that this kind of
kernel design is unacceptable - all the hardware works just fine with
DMA.
Afterwards, the disk had 4 more reallocated sectors. Badblocks'
opinion? "Problem? What's that?" As a tool it's not any more useful
than dd, cat, or syslog, these days anyway, though I've heard some
people use it successfully to test new machines before putting them
into service (and that was years ago too). It was very useful in the
days of 50MB disks without cache (see its default of 16 for -c). These
days disks either work or get replaced. Bad blocks scanning is
essentially a thing of the past.
(I'm not complaining, just saying that if people expect badblocks to
tell them their bad blocks, they're running a high risk of being
disappointed.)
Volker (going off for a new disk soonish)
--
Volker Kuhlmann is possibly list0570 with the domain in header
http://volker.dnsalias.net/ Please do not CC list postings to me.
