Performance Degradation with Data Assurance enabled Volumes and iSCSI
Applies to
- Controller Firmware (SANtricity OS) 11.40.x and later
- iSCSI volumes with Data Assurance enabled
- iSCSI initiator
- Controllers:
- E28xx or EF280 using baseboard iSCSI ports
- E28xx or EF280 using iSCSI ports on host interface card orderable as “HIC,E2800,16G FC/10GbE,4-ports “
- E57xx using baseboard iSCSI ports only
Issue
- Starting with E-Series controller firmware 11.4x and including releases thereafter (i.e. 11.5x), the Data Assurance (DA; T10 PI) feature is now available with iSCSI on controllers models E28xx and E57xx/EF57x and enabled by default on volumes.
- Due to a hardware limitation of the QLogic Hilda chipset, having DA enabled on an iSCSI volume can cause a performance degradation in read scenarios. This scenario does NOT affect the 25Gb chipset.
- When using an iSCSI initiator to issue Reads to an iSCSI volume with DA enabled, you may experience Read performance degradation compared to a non-DA enabled iSCSI volume. The degradation is more noticeable if queue depth=1.
- Operations such as datastore creation may time out or fail.
- Opening a folder on VMs running at VMware ESXi using E-Series volume datastore could take about 1 minutes.