A 200G drive in one of my RAID systems failed today. Since it was RAID 5, no data was lost. However, the original drive had an actual capacity of 203G, while new ones sold with the identical part number are only 200G even. So I can’t put an “identical” replacement in; I’ll have to get a 250G drive.
The failed drive was acquired second-hand and had previously been used for life cycle testing, so it is not too surprising that it failed since it was subjected to abnormally high wear. I didn’t expect that these particular drives would be very reliable, given their history, so I was only willing to use it in a RAID 5 configuration.