When the GAD status is Mirroring or Quorum disk blocked, and the I/O mode for the S-VOL is Block. The I/O mode and the I/O flow vary depending on the microcode or firmware version.
When the GAD status is Mirroring or Quorum disk blocked or no volume is set for the quorum disk, the I/O mode for the P-VOL is Mirror(RL), and the I/O mode for the S-VOL is Mirror(RL).
Write requests are written to both pair volumes and then the write-completed response is returned to the server.
Read requests are read by the P-VOL or S-VOL and then sent to the server.
