User mode : 300MB(excepting for optional products.)

When the synchronization mode is used:
1024 KB + (number of request queues x I/O size) + 2448 KB x number of mirror disk resources and hybrid disk resources

When the asynchronous mode is used:
1024 KB + (number of request queues x I/O size) + (3072 KB + (number of asynchronous queues x I/O size) + (I/O size / 4 KB x 8 B + 0.5 KB) x (max size of history file / I/O size +  number of asynchronous queues) + 400 KB ) x number of mirror disk resources and hybrid disk resources

When the kernel mode LAN heartbeat driver is used:
8MB

When the keepalive driver is used:
8MB

(*) Estimated I/O size is as follows:
     - 6MB (RHEL 10)
     - 6MB (RHEL 9)
     - 1MB (RHEL 8)
(*) The I/O size varies depending on the server performance and the written amount. Theoretically speaking, the maximum I/O size is as follows:
     - 4GB (RHEL 10)
     - 4MB (RHEL 9)
     - 2MB (RHEL 8)
(*) For the setting value of the number of request queues and asynchronization queues, see "Understanding Mirror disk resources" of "Group resource details" in the "Reference Guide".
(*) For the required size of a partition for a disk heartbeat resource, see "Shared disk".
(*) For the required size of a cluster partition, see "Mirror disk" and "Hybrid disk".

Right after installation : 300MB
During operation : 5.0GB + 1.0GB(A disk capacity required to use mirror disk resources and hybrid disk resources.)