So what makes the VFusion system so reliable? Here are some key differences to traditional filesystems
Small data corruption
Small data corruption may happen at any time and in fact it does happen often, even on enterprise-class drives.
Standard disks redundancy (RAID or mirror) does not protect against silent corruption.
Filesystem receives damaged data that is further passed to an application which operates on corrupted data.
output is worthless
Silent data corruption prevention in ZFS
Application issues a read. ZFS mirror tries first disk. Checksum reveals that the block is corrupted on the disk.
ZFS tries second disk. Checksum indicates that the block is good.