Online expansion methods when LUNs cannot be detected on the host of an OceanStor V3 storage system

Cause: The disk enclosure that encounters a power failure is a sub-group of RAID 10. Data can also be written into other sub-groups. However, if a disk enclosure encounters a power failure, the metadata logs of more than three disks are recorded. Currently, the RAID 1 group has only four disks. Therefore, the logs of a maximum of four disks are recorded. If the logs of extra three logs must be recorded, the logs fail to be recorded and an I/O failure is returned to the host. Solution: Power on the disk enclosure to solve the problem.

After a host group and a LUN group are added to a mapping view, the application server, host group, and LUN group are logically associated. Then the application server can detect the LUN in the LUN group. For details about creating a mapping view, click Creating a Mapping View .

If Huawei UltraPath is installed on the host, run the hot_add command to scan for disks. The existing services will not be affected. If the multipathing software is not installed, use the iSCSI network and restart the iSCSI service. If the Fibre Channel network is used, restart the server.

For details on how to expand LUNs on the DeviceManager, and then detect LUNs on the host to identify the expanded LUNs, see Expanding a LUN .

Refer to Revelations of Troublesolving cases on the right.