Depending on pairing of CA ports and failover, the port parameter and Link status of CA ports are changed. The device whose Link status is "Linkup" is accessible from Managed Servers.
For FC connection environments, the value of WWPN/WWNN is changed by pairing CA ports.
For iSCSI connection environments, manually setting the parameter of the iSCSI CA port of the Secondary Storage to match that of the Primary Storage after a CA port pairing can control the Link status.
Change in Link status of each CA port with CA port pairing and failover/failback operations are shown in "Table 9.6 Change in Link Status of CA Port (for FC Connection Environment)" and "Table 9.7 Change in Link Status of CA Port (for iSCSI Connection Environment)".
Primary Storage | Timing | Secondary Storage | Secondary Storage | |||
|---|---|---|---|---|---|---|
WWPN/WWNN | Link Status | Link Status | WWPN/WWNN | Link Status | WWPN/WWNN | |
WWPN/WWNN of the Primary Storage side | Linkup | Pre-CA port pairing | Linkup | WWPN/WWNN of the Secondary Storage side | Linkup | WWPN/WWNN of Secondary Storage side |
Post-CA port pairing | Linkdown when REC starts Linkup after equivalence is completed | Linkdown | WWPN/WWNN of the Primary Storage side | |||
Linkdown | Primary Storage stops | Linkup | ||||
Under failover | ||||||
Failover completed | Linkup | |||||
Primary Storage recovered | ||||||
Failback started | ||||||
Under failback | Linkdown | |||||
Linkup | Failback completed | |||||
Storage Cluster deconstructed | Linkup | WWPN/WWNN of the Secondary Storage side | ||||
*1: When returning the WWPN/WWNN of the Secondary Storage CA port to its original status.
Primary Storage | Timing | Secondary Storage | ||
|---|---|---|---|---|
iSCSI Information | Link Status | Link Status | iSCSI Information | |
iSCSI information of the Primary Storage side | Linkup | Pre-CA port pairing | Linkup | iSCSI information of the Secondary Storage side |
Post-CA port pairing | Linkdown | |||
Parameter setting of iSCSI CA port of the Secondary Storage side | iSCSI information of the Primary Storage side | |||
Linkdown | Primary Storage stops | |||
Under failover | ||||
Failover completed | Linkup | |||
Primary Storage recovered | ||||
Failback started | ||||
Under failback | Linkdown | |||
Linkup | Failback completed | |||
Parameter setting of iSCSI CA port of the Secondary Storage side | iSCSI information of the Secondary Storage side | |||
Storage Cluster deconstructed | Linkup | |||
*1: The Active-Active configuration is not supported in iSCSI connection environments.
About CA Port WWPN/WWNNs of the Secondary Storage when deconstructing a Storage Cluster Environment
If such a trouble as requires storage device replacement occurs and an ETERNUS Disk storage system should be replaced, deconstruct the Storage Cluster environment by deleting TFO groups.
For FC connection environments with the Active-Standby configuration, when deleting TFO groups, you can select either of the following actions to handle WWPN/WWNN of the CA port for the Secondary Storage:
Return the Secondary Storage CA port to its original WWPN/WWNN.
Return the Secondary Storage CA port not to its original WWPN/WWNN but continue to use the logical WWPN/WWNN.
If Step "a" is selected, it does not compete with the WWPN/WWNN of the Primary Storage CA port.
If Step "b" is selected, the device operated as the Primary Storage can be replaced while the Secondary Storage is accessible from Managed Servers.
Note
For FC connection environments with the Active-Standby configuration
If both the Primary Storage CA port and the Secondary Storage CA port get active, their WWPN/WWNN competes with each other, possibly causing data corruption. Therefore, when selecting Step "b", keep the following rules:
Do not delete the TFO group before making sure that the Primary Storage CA port is physically disconnected from SAN.
Do not connect to SAN the ETERNUS Disk storage system that had the Primary TFO group deleted.
For iSCSI connection environments
The set values for the iSCSI name and the iSCSI IP address remain unchanged. Therefore, keep the following rules:
Check whether the iSCSI IP address is not a duplicate in the same SAN. If it is a duplicate, do not delete the TFO group before changing the iSCSI IP address.
Do not delete the TFO group before making sure that the storage device in the standby side is physically disconnected from SAN.
