Clonezilla is the disk copying tool used to replicate the drives across slave nodes. See Clonezilla Step-by-Step guides for a how-to guide on disk-to-disk cloning. Inside Minotaur's server rack is an external HDD and a USB. Clonezilla is on the USB, and a copy from a slave node is on the HDD. Reboot a working (and up to date) node with the Clonezilla USB and copy its drive (sda#) to the external HDD (sdb#). The External HDD is much larger than the slave node therefore select Expert-cloning method and under advanced options select "use the partition from the image." Then boot the failed node using Clonezilla and perform the reverse operation, copying the external HDD (sdb#) to the internal drive (sda#). Copying may take a while, up to 2Hrs. Because the target drive is now smaller than the source drive, select the expert method and highlight the option "[*] -icds Skip checking destination partition size before creating partition table." Make sure "use the partition table from the image" is also selected.
Now two nodes are exact copies of each other. This is of course not acceptable. Using root privilege the repaired node then needs to be relabeled.