NetWare allows you to protect your data with disk mirroring or duplexing.

Mirroring stores the same data on separate disks on the same controller channel; duplexing stores the same data on separate disks on separate controller channels.

Duplexing is the preferred method since two channels rarely fail simultaneously.

Do not mirror a partition on a disk to another partition on the same disk. Doing so is not fault tolerant, even though mirroring allows it.

With multiple partitions on a disk, any partition can be mirrored to any other disk. This provides considerable flexibility in protecting partitions.