Canisters are hardware units that are subcomponents of enclosures.
The system has two types of canisters: node canisters and expansion canisters. A node canister provides host interfaces, management interfaces, and interfaces to the control enclosure. When a system is viewed from the back, the left node canister is identified as canister 1. The right node canister is identified as canister 2. A node canister has cache memory, internal drives to store software and logs, and the processing power to run the system's virtualizing and management software. A node canister also contains a battery that helps to protect the system against data loss if a power outage occurs.
An expansion canister provides the serial-attached SCSI (SAS) connectivity to the drives in an expansion enclosure. Each expansion enclosure contains a pair of expansion canisters to provide redundancy. An expansion canister does not contain a battery.
To access information about the canister in the management GUI, select . On the System - Overview page, click the directional arrow next to the enclosure that contains the node canisters. On the Enclosure Details page, select Node Canister under Rear View to highlight and display information on the node canisters. To display information about the canister in the command-line interface, use the lsenclosurecanister command.