I bought a USB 2.0 hard disk enclosure (for both PATA & SATA 3.5") and put my WD1600JB 160G ATA hard disk in for backup. I copied a couple of 1GB files onto it (no errors reported). Later, I compare the files with the origins and they were different. Then, I ran md5sum checking on those files and it failed about once in three/four times. It seems that the transfer of large files from the external drive (maybe both direction) was unreliable.
The whole thing was tested on 3 different computers and USB cables but no luck. But the hard disk was okay with direct IDE connection. What should I check further? Should I get another USB enclosure? It's weird that no errors were reported by Windows. Is it supposed error checking/correction mechanisms are built in the I/O (USB and IDE)?
Basically doing any backup especially for system one should test the whole backup and recovery process. This makes sure every thing goes right for that purpose. Otherwise, you spend time on it every week and one day all luck is gone and you find that it doesn't work as expected.
I should have paid 50% more for a reliable storage media that would save me lots of time.