check for badblocks

[ccc]

hi

howto check freeBSD 7.0 for badblocks ?
is it possible to start the badblocks check on running freeBSD without damage the system ?

[J65nko]

Go to the website of the manufacturer of your disk and download an utility to scan the drive for bad blocks. (Usually a MS-DOS or Windows utility)

If you want to pay some bucks and make Steve Gibson rich, get his Spinrite program from grc.com

[vermaden]

You can do it like that:

% dd < /dev/ad0 > /dev/null

it will read every block of your hard drive, if you get any read errors, then you have bad sectors.

You can also try to "fix" these bad sectors with gshred from coreutils package:

# gshred --verbose /dev/ad0

But keep in mind that gshred will erase all your data from this drive.

[graudeejs]

man dd example section says?:

     Check that a disk drive contains no bad blocks:

	   dd if=/dev/ad0 of=/dev/null bs=1m

     Do a refresh of a disk drive, in order to prevent presently recoverable
     read errors from progressing into unrecoverable read errors:

	   dd if=/dev/ad0 of=/dev/ad0 bs=1m

[ccc]

thx,

can I check the system for bad sectors (just a test) using read only option
on a running system without single mode or unmout the partitions ?

[vermaden]

yes, with that:
% dd < /dev/ad0 > /dev/null