How to make smartd shut up about one particular offline uncorrectable sector?

On a some disks, you might have to resort to -U 198+ (or -U + ?) in the config file.

Please be careful. If you are not the original asker, read through the whole question carefully. If you use this on a disk which does not need it, it will suppress entirely valid warnings.

If ´+´ is specified, a report is only printed if the number of sec‐ tors has increased since the last check cycle. Some disks do not reset this attribute when a bad sector is reallocated. See also ´-v 198,increasing´ below.

smartd.conf (5)

For example, suppose you are using the default configuration in smartd.conf. In that case, there are many comments in the file, but the only non-comment line is here:

# The word DEVICESCAN will cause any remaining lines in this
# configuration file to be ignored: it tells smartd to scan for all
# ATA and SCSI devices.  DEVICESCAN may be followed by any of the
# Directives listed below, which will be applied to all devices that
# are found.  Most users should comment out DEVICESCAN and explicitly
# list the devices that they wish to monitor.
DEVICESCAN

Add the option to the end of the line:

DEVICESCAN -U 198+