I have just come across something a bit disturbing. I copied 200GB from one machine to another and then ran sum on the copied files. Some of the had differing checksums (the size was thee same) The config of two machine are:- 1) kernel-2.2.14 unified ide patch 2.2.14-B1 raid patch 2) kernel-2.4.0-test1 Neil Brown's autodetect patch Both machine have a raid5 stripe across 10 ide disks, the disks sit on 4 promise ultra66's, and the two onboard intel controllers, using only the master of each channel. Does anybody have any suggestions of how I could approach finding out where the corruption is happening. thanks -- Franc Carter MEMLab, University of Sydney Ph: 61-2-9351-7819 Fax: 9351-6461