2015-10-07 0:45 GMT+08:00 Ted Unangst <t...@tedunangst.com>: > Mikael wrote: > > The script below includes extra considerations to see through any kernel > > caching of the disklabel, by rebooting between every relevant step. > > > > "dd if=/dev/srandom of=/dev/rwd0e bs=1024 count=1" does also wipe the > > disklabel. > > > > "dd if=/dev/srandom of=/dev/wd0a bs=1024 count=1" does not wipe the > > disklabel. > > > 16 partitions: > > # size offset fstype [fsize bsize cpg] > > a: 3907008000 16065 RAID > > c: 3907029168 0 unused > > e: 16001 64 RAID > > yes, if you overwrite the disklabel (which lives at the start of the disk) > you > will wipe it. don't do that. >
But.. wd0e is the "e" partition within the BSD disklabel, and that's what I wrote to (and even if it's not relevant here, also its writes should be "boundary checked" so they're foolproof in respect of overwriting extra-partition data)? With "dd if=/dev/srandom of=/dev/rwd0*c* bs=1024 count=1" I'd have understood that I wiped something sensitive, but this is "dd if=/dev/srandom of=/dev/rwd0*e* bs=1024 count=1"?? Have I (and some others) misunderstood anything about how BSD disklabelling works?
