Checking the hard disk FreeBSD on broken sector. utility ddrescue

How to check the hard drive in the FreeBSD broken sector (bad-blocks)? You can use the utility dd_rescue.
Install it:
# Cd / usr / ports / sysutils / dd_rescue
# Make install clean
# rehash

You can look in the file / etc / fstab to mount the partitions and disks, you can use the mount. So, figured out which device to check, let’s start:
# Dd_rescue -v -l error.log -o bad.log / dev / ad0s1a / dev / null

In the process you can clearly observe the emergence of errors and their quantity. Also, the entire log is written to the file error.log, and broken sector in the file bad.log