Bad sectors: how bad can it be

Michaël Grünewald michaelgrunewald at
Wed Oct 28 19:55:27 UTC 2009

Polytropon wrote:
> On Tue, 27 Oct 2009 21:05:39 +0100, Michaël Grünewald <michaelgrunewald at> wrote:
>> I have however a question: How do I verify that 
>> a hard-drive is accurately working if its firmware will hide the bad 
>> sectors as long as possible?
> I think the smartctl program from ports/smartmontools is 
> a good tool for such verification. As far as I understood,
> it can read internal error logs from the firmware.

Hi, following your suggestion I used smartmon to get access to the SMART 
data. I have run an extended offline test (with-t offline I think). The 
test reported no error (!) and the bad sectors are now read/writeable 
(!!). Is it safe to think the problem is gone?

# smartctl -l selftest /dev/ad10

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining 
LifeTime(hours)  LBA_of_first_error
# 1  Extended offline    Completed without error       00%       458 
# 2  Extended offline    Aborted by host               70%       456
Best regards,

More information about the freebsd-questions mailing list