If the write-pending rate of a storage system to which the quorum disk (external volume) at the primary or secondary site is assigned is high, the I/O performance of the GAD pair volumes might decrease or the GAD pairs might be suspended by some failure.
To address this situation:
- Use Export Tool 2 on the primary or secondary storage system to perform regular monitoring of the write-pending rate of each storage system to which the quorum disks are assigned.
- If the write-pending rate exceeds 70%, review your configuration and consider the following actions:
- Lower the I/O load in the storage system.
- If the cache load is high:
- Lower the I/O load.
- The cache write pending rate might exceed 70% temporarily due to failures on the primary and secondary storage systems. To prevent the I/O performance of the GAD pair volumes from decreasing or the GAD pairs from being suspended by failures related to this situation, the write-pending rate should be below 35% for each storage system under normal conditions.