Introduction to the spill over function of OceanStor 9000 V100R001C01

OceanStor 9000 data balancing refers to the balancing of data capacity on storage nodes. After a disk or node is added, you can migrate it to make data evenly distributed on all storage nodes. OceanStor 9000 provides two modes of data balancing: - Manual balancing: After a data balancing task is manually started, the system checks whether data in each node pool is balanced in the system. If data is unbalanced, the system starts a data balancing task. - Automatic balancing: After a disk or node is added, the system waits 30 minutes and then starts a data balancing task. If the waiting time is shorter than 30 minutes and more disks or nodes are added, the system waits another 30 minutes before starting a data balancing task.

The software architecture of OceanStor 9000 V100R001C01 is as follows: The software architecture is fully symmetric with WushanFS run on all storage nodes. Metadata is evenly distributed to eliminate performance bottlenecks. OceanStor 9000 supports the seamless flexible expansion of 3 to 288 storage nodes and enables file system capacity to be expanded up to 40 PB. OceanStor 9000 provides NFS, CIFS, and FTP services, enabling clients running different operating systems to share files. Two types of client authentication modes are supported, local authentication and domain server authentication based on Active Domain (AD), Lightweight Directory Access Protocol (LDAP), and Network Information Service (NIS). Administrators can securely access DeviceManager and OceanStor SystemReporter (an optional report tool) to manage system resources and monitor system status and performance through HTTPS.

In OceanStor 9000 V100R001C01, the default high watermark is that the used space occupies 85% of the total storage space of a node pool. When the used space of a node pool reaches the high watermark, the system reports a capacity insufficiency alarm, and refuses data to be written to the node pool. By default, the alarm clearance threshold is 5% lower than the high watermark. That is, when the percentage of used space is lower than 80%, the capacity insufficiency alarm is cleared. The alarm threshold and clearance threshold of the high watermark can be manually changed.

In OceanStor 9000 V100R001C20 and V100R001C30, when the used capacity of a node pool reaches the read-only watermark and the spill over function is enabled, data cannot be written to the node pool but can be written to other node pools or a node pool specified by spill over. If the used capacity of a node pool specified by spill over exceeds the read-only watermark, data cannot be written to the node pool. When the used capacity of a node pool reaches the read-only watermark and spill over function is not enabled, data can be written neither to the node pool nor to any other node pool.