Planning the Expansion
Work out a plan before adding controllers to facilitate follow-up operations.
Table 10-1 describes items to be planned before you add controllers.
Item |
Sub-Item |
Description |
|---|---|---|
Controller enclosure |
Controllers to be added for expansion |
The new controllers should have the same CPU model, memory specifications, disk capacity, and software version number as the original controller. WARNING:
Ensure that the controllers you want to add are new devices purchased through the standard purchase order (PO). Otherwise, the controllers will fail to be added. NOTE:
|
Interface module |
25 Gbit/s RDMA interface module |
25 Gbit/s RDMA interface modules are used for communication between controllers. NOTE:
|
Networking mode |
Direct-connection networking |
Applies to the expansion from two to four controllers. |
IP address |
IP addresses of management ports on the storage system |
|
IP addresses of management ports on the storage system after controllers are added |
After controllers are added, still use the IP address of the management network port on controller enclosure 0 to log in to the storage system. NOTE:
After adding controllers, you can re-configure the IP addresses of the management network ports on DeviceManager. For details, see "Changing IP Addresses of Management Network Ports Using DeviceManager" in Installation Guide. |
|
IP addresses of iSCSI front-end ports |
IP addresses of iSCSI front-end ports are used for service data communication between iSCSI front-end ports and hosts. |
|
Service IP address outside the cluster |
IP addresses outside the cluster are used for service data communication outside the cluster. |
|
Multipathing software |
- |
If a host uses Symantec Veritas DMP 5.1 SP1 to 7.4 multipathing software and the host's storage device does not enable the A/A working mode, you must stop host services before expanding controllers from 2 to 4 or more controllers. Use either of the following methods:
|
- Before the controller expansion, Huawei technical support engineers are advised to apply for a spare controller before the capacity expansion to prevent a faulty controller from affecting capacity expansion.
- Before performing capacity expansion, ensure that the IP addresses of management network ports, internal heartbeat, and iSCSI front-end ports as well as the service IP address outside the cluster do not reside in the same network segment. Otherwise, an IP address conflict occurs. Run show port ip to query the IP addresses of Ethernet ports (including iSCSI front-end ports and management network ports). Run show host general to query the service IP address.
- Internal heartbeat links are established between controllers to detect each other's working status. You do not need to separately connect cables. The internal heartbeat IP addresses are assigned before delivery and cannot be changed.
- You are not allowed to disconnect a disk enclosure from a storage system's controller enclosure that has connected to it and connect the disk enclosure to another controller enclosure of the storage system.
