> On 18/04/2008, Calomel <avertege@calomel.org> wrote:
> > Ropers,
> >
> > You can find the badblocks utility prepackaged in "e2fsprogs".
>
> THANK YOU! :) I had wondered why I couldn't find badblocks among
> OpenBSD's packages. This explains it. I will say in my defense ;-)
> that badblocks is not ext2-specific, so while I have now seen that
> it's part of these tools, possibly for historic reasons, that's not
> necessarily a logical place for it to be.
>
> Looking at the package contents (
>
http://www.openbsd.org/4.2_packages/i386/e2fsprogs-1.27p5.tgz-contents.html
> ), I've also figured out how to search for stuff like this in the
> future:
>
>
http://www.google.ie/search?q=badblocks+inurl%3Aopenbsd.org+inurl%3Acontents.html&btnG...
>
> I was surprised though to find that GoogleBot doesn't appear to have
> indexed most of these pages -- maybe because
>
http://www.openbsd.org/<x.y>_packages/<architecture>.html loads so
> slowly?
>
> > BadBlocks Hard Drive Validation and/or Destructive Wipe
> >
http://calomel.org/badblocks_wipe.html
>
> Thanks for this info as well. I wonder why googling openbsd and
> badblocks didn't turn that up for me.
>
> On 18/04/2008, Jon Simola <jsimola@gmail.com> wrote:
> > On 4/18/08, ropers <ropers@gmail.com> wrote:
> > > Sometimes I find myself in need of a disk checking utility that can
> > > check both disks with known *and unknown* filesystems, and/or that can
> > > check even currently unpartitioned space on a disk.
> >
> >
> > Not claiming to be an optimal solution (dd is faster), but does a read
> > pass across the
> > entire partition:
> > $ sudo md5 /dev/rwd0c
> > MD5 (/dev/rwd0c) = a85c2c67475f983a98007fd9a47378b7
> >
> > Run it again and compare the hashes if you're worried.
> >
> > Works on floppies too, broken ones can't be read:
> > $ sudo md5 /dev/fd0c
> > md5: /dev/fd0c: read error: Input/output error
> > $ tail -n1 /var/log/messages
> > Apr 18 13:13:29 gamma /bsd: fd0c: hard error reading fsbn 0 of 0-3
> > (st0 40<abnrml> st1 20<bad_crc> st2 20<bad_crc> cyl 0 head 0 sec 1)
> >
> > In OpenBSD the 'c' partition covers the entire disk, so you'll
> > probably want that most of
> > the time. dd is very useful for this as well, but read the man pages carefully.
>
> Ah! Those are also very good thoughts! Now Steve rightly observed that
> I wanted to do a write-test, but come to think of it, something like
> this should allow one to do a "badblocks -svn"-alike non-destructive
> write test:
>
> - Use dd to back up the entire device to /tmp.
> - then copy /dev/arandom (or even /dev/srandom) to the device until
> it's full and use tee to also duplicate what's being written to the
> device to /tmp.
> - md5sum the latter, duplicate file in /tmp
> - md5sum the device, compare the hashes (& delete the file)
> - finally, dd the original backup file back to the device and delete the backup.
>
> This kludge could be used as a poor man's badblocks, if that's not
> available, but it does require that twice the size of the device is
> available in terms of disk space.
> Yes, it's kinda horrible and probably useless in most situations, but
> there we go. ;-)
>
> Thanks and regards,
> --ropers
>
>
