Replication QoS Advanced Settings

• Global Maximum Sectors Per IO: The number of sectors to transfer in a single I/O request, which determines the maximum size of an I/O request. Larger values cause less "chopping" (larger chunks of data will be sent on the wire.) If this value is set too high, the target side's write cache may be bypassed.
• Global Maximum Number of IOs: The total number of outstanding I/O requests allowed. This is related to the execution throttle set in the HBA. The iSCSI protocol limits the number of outstanding requests to 64, so setting this value any higher will have no effect on iSCSI transports.
• Global Maximum Number of Sectors: The total number of outstanding sectors allowed. This determines the total amount of data on the wire at any given time; if (sectors per I/O * number of I/Os) is greater than this value, outstanding I/Os are limited.
• Destination Maximum Number of IOs: The number of outstanding I/Os allowed per destination.
• Destination Maximum Number of Sectors: The number of outstanding sectors allowed per destination.
• Maximum IOs Per Queue Pass: The number of I/Os to satisfy at each pass through the system queue, relevant on a per destination basis. If there are multiple volumes to a single destination, outstanding I/Os are serviced from the first volume, then the second, and so on, until this number is reached. Smaller values ensure that all volumes to a destination get serviced often.
• Maximum Sectors Per Queue Pass: The number of sectors allowed to a destination at each pass through the system queue. Smaller values increase fairness at the expense of CPU utilization.