When a pool is created, it is intrinsically tied to the host system. The host system maintains information about the pool so that it can detect when the pool is unavailable. Although useful for normal operations, this information can prove a hindrance when you are booting from alternate media or creating a pool on removable media. To solve this problem, ZFS provides an alternate root location pool feature. An alternate root pool location does not persist across system reboots, and all mount points are modified to be relative to the root of the pool.