This just means that you have one bad sector on one drive in your RAID array. There is nothing to worry about at the moment, unless you start getting a lot more bad sectors on that disk. You should NOT try to manually fix the error...that will be done automatically on the first of each month by the raid-check command, which is run from /etc/cron.d/raid-check. You can check that command and run it manually to immediately reallocate the bad sector on the disk:
[root@server]# more /etc/cron.d/raid-check 0 1 * * Sun root /usr/sbin/raid-check[root@server]# /usr/sbin/raid-checkThis will force mdraid to copy the bad block from the other disk in the RAID array, and it will mark the bad block as unusable.
