On Sat, Sep 20, 2008 at 10:28:07PM -0700, Aaron Stellman wrote: > On Sun, Sep 21, 2008 at 06:02:37AM +0100, Sunnz wrote: > > OK I am trying to completely erase the data of a hard disk so I though > > I can just do `dd if=/dev/arandom of=/dev/rwd0c` as to my > > understanding that is the entire hard disk (slice c) of wd0 in 'raw' > > mode? > > > > But that dd refuse to do it. > security(7): > "Once you have set the security level to 1, write access to raw > devices will be denied"
I guess you're quoting from a FreeBSD man page. On OpenBSD, securelevel(7) says that in securelevel 1, raw disk devices of mounted file systems are read-only. It's securelevel 2 that denies write access to all devices. Sunnz says he's running off an install CD so he should not run into problems related to securelevel. I guess he's root too. Sunnz, you don't say exactly what error dd reports. Have you created the arandom character device file? It is not available by default on the install CD. > > > > So now I am doing the same thing but to wd0c instead. Is this any > > worse? This is the "character device" right? Does that mean dd won't > > write random bits as low as going to the raw device? > > > > This is running off a OpenBSD 4.3 CD, there are no intention to > > actually destroy the hard disk in any way, just erasing the data off > > the hard disk so that it can be reused, re-sold, whatever. The data > > are not some military top secret, but it is interesting to know of > > what can be done in a home/small office environment when it comes to > > erasing the hard drive. > > > > Thanks. > > > > -- > > This e-mail may be confidential. You may not copy, forward, > > distribute, or, use any part of it. Note, like all disclaimers on the > > net, there are no effective legal binding on your part and disclaimers > > can be ignored. For more information about disclaimers, please see: > > http://www.goldmark.org/jeff/stupid-disclaimers/
