What action is to be taken in case of disk error?

Regular report in Email notification function: DISK error status

[DISK error status] For example, "DISK3 1"means a read error was detected once in the Disk3.

In case the error counter indicates a small number such as "1", an immediate disk replacement is not required.
A successive frequent disk error in the same disk may cause an entire disk failure. An early replacement is recommended.

An increase of the read error count makes the following message appear.

"HDx Error E15 Many Bad Sector"

Example:
[TeraStation Information]
TeraStation name: TeraStation
Date: 2011/01/04 00:00:01
IP address: 192.168.11.150
set-up menu: http://192.168.11.150/
continuous operation duration : 70 days, 16:53:03

[Hard Drive usage status]
RAID array 1 used volume: 1252660616 kbytes / 4349962368 kbytes (ratio in use: 29%)

[DISK error status]
DISK1 0
DISK2 0
DISK3 1
DISK4 0