Ditto data blocks in ZFS
The ZFS implementation in ZFS build 61 contains an really interesting new feature: redundant copies for data. You can define an per filesystem basis, that zfs makes redundant copies of data besides of RAID protection. It´s a quite powerful feature. One obvious use case are laptop: You have only one hard disk. So RAID is somewhat out of consideration. With a single command (
zfs set copies=2 zfspool/homedirectories) you can configure a filesystem for your important data to ensure that every datablock of it exists twice on the hard disk,</a> while easily recoverable data like the operating environment exists only one time on your harddisk. But before i generate a RECF (Redundant Explanation of a Cool Feature) i suggest, that you look at this excellent article in Richard Ellings blog:ZFS, copies, and data protection.