Writes to Hard Disk Going Beyond Capacity

Patrick Donnelly batrick at batbytes.com
Sat Jul 10 10:53:49 UTC 2010

On Sat, Jul 10, 2010 at 4:01 AM, Giorgos Keramidas
<keramida at ceid.upatras.gr> wrote:
> On Sat, 10 Jul 2010 03:10:31 -0400, Patrick Donnelly <batrick at batbytes.com> wrote:
>> Hi List,
>> I have a strange problem in a C program I wrote. I open a hard
>> disk character file (/dev/ad1) and attempt to write over the
>> entire disk. I expect the last write that would go beyond the
>> hard disk length (capacity) to return with an error but instead
>> the write succeeds.  This happens for hundreds of gigabytes
>> beyond the file (hard drive) length. What could be wrong? (This
>> program works fine on Linux. The last write that would go
>> beyond the end of the hard drive returns with -1.)
>> Thanks for any help,
> Can we see the exact source code of the program?  What you
> describe might work if the file has holes inside it.


Specifically, after filling the hard drive it will begin to rapidly
"write" where the throughput of the writes is about 10 GB/s (obviously
not going to the hard drive).

- Patrick Donnelly

More information about the freebsd-questions mailing list