The Data Copy That Lies

Unix Universe, on silent data corruption and the architectural decision behind ZFS. A study by Bairavasundaram and colleagues at USENIX FAST 2008 examined 1.53 million disk drives over 41 months and recorded more than 400,000 checksum mismatches, eight per cent of which were discovered during RAID reconstruction, when the redundancy meant to protect the data had already been spent; the paper…