I assume you are talking about physical bad blocks on a disk and not about corrupted file systems.
To check the physical condition of your disk it's best to install
sudo apt-get install smartmontools
This works because all modern disks log their health status using a system called S.M.A.R.T.
smartctrl command to read out this status. For example to read all attributes from the first disk call
sudo smartctl --all /dev/sda
Watch out for a line talking about the overall heath status. Once this indicates an error it's very likely that the disk will fail soon.
SMART overall-health self-assessment test result: PASSED
Other lines you want to check for are the Pending Sector Count and the Reallocated Sectors.
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 48
197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 2
Reallocated lists usually in the raw field the number of bad sectors the disk exchanged for working spare ones. Pending are sectors which might be reallocated in case the next write fails.
You can even trigger self tests of the disk when supported by your model
sudo smartctl -t long /dev/sda
To force checking of all sectors, use
badblocks in a mode in which data is written. Beware that even though in general it is safe to run, it will put extra load on your disks, which might cause them to fail. Always have a backup of your data.
sudo badblocks -svvn -c 262144 /dev/sda
The output from the
badblocks command will show you many lines with
hh:mm:ss elapased. (x/y/z errors)
x = num_read_errors
y = num_write_errors
z = num_corruption_errors
If you have fully processed your disk this way, the disk controller should have replaced all bad blocks by working ones and the reallocated count will be increased in the SMART log.