CES iSCSI support
The CES BLOCK service provides iSCSI protocol support.
You can export a file resident in a GPFS™ file system as a virtual iSCSI volume to an iSCSI initiator by using the iSCSI protocol. The iSCSI protocol in IBM Spectrum Scale™ is referred to as the CES BLOCK service. iSCSI support in IBM Spectrum Scale is intended for remotely booting nodes (non-performance-critical), and is not intended for high-bandwidth block device workloads. Before using the iSCSI protocol, confirm that this matches your use case, or contact scale@us.ibm.com with any question regarding the supported use cases.
Clustered BLOCK service
iSCSI initiators can connect to any protocol node and access the virtual iSCSI volume. A clustered registry ensures that all nodes have the same configuration data. If a CES IP failover is triggered, an iSCSI initiator reconnects transparently to another CES node.
BLOCK service management command
The mmblock command provides a comprehensive entry point to manage iSCSI targets and volumes. The block service configuration is controlled by the SCST configuration files. The master version of these files is stored in the CCR, and copies exist in /etc/scst.conf on each protocol node. Do not modify the /etc/scst.conf file directly because it is overwritten by the information stored in the CCR.