You can't really. But it's a pretty safe bet with the big guys. I doubt it's anything to worry about. Backblaze actually documented how they handle their filesystems and their strategies against data corruption here. Pretty interesting. Someone actually asked about ZFS since Backblaze actually use EXT4, and there is some good info there. FYI: For anyone who doesn't know, Backblaze are well known for using consumer drives rather than enterprise stuff. They're able to do that using the unique parity checking systems they've implemented. Pretty clever, and probably saves them quite a wad of cash.