Disk storage configuration and HA
If your cluster units include storage disks (for example for storing log messages, WAN optimization data and web caching) all cluster units must have identical storage disk configurations. This means each cluster unit must have same number of disks (including AMC and FortiGate Storage Module (FSM) hard disks) and also means that matching disks in each cluster unit must be the same size, have the same format, and have the same number of partitions.
In most cases the default hard disk configuration of the cluster units will be compatible. However, a hard disk formatted by an older FortiGate firmware version may not be compatible with a hard disk formatted by a more recent firmware version. Problems may also arise if you have used the execute scsi-dev command to add or change hard disk protections.
If a cluster unit CLI displays hard disk compatibility messages, you may need to use the execute scsi-dev delete command to delete partitions. You can also use the execute formatlogdisk command to reformat disks. In some cases after deleting all partitions and reformatting the disks, you may still see disk incompatibility messages. If this happens, contact Fortinet Customer Support for assistance.