What does it mean: [3ware 3DM alert -- host: debpro]

[Jacob Larsen <lists@debpro.webcom.dk>]

Anyone know what this means?

-------- Original Message --------
Subject: 3ware 3DM alert  --  host: debpro
Date: Thu, 23 Sep 2004 06:31:45 +0200 (CEST)
From: support@webcom.dk <support@webcom.dk>
To: support@webcom.dk

WARNING: Drive sector ECC error corrected on port 0 on controller ID:0. 
(0x23)

source: debpro