On the FusionCompute V1R5C10SPC700 enviroment, the customer is not using these LUNs but he can't delete the LUN mapping from storage.
Storage Type: S3900
When the customer trying to remove the LUN from the hostgroup on storage, He get the error that the “there are still some IO communication” and the delete operation failed.
1. If the customer want to delete lun from storage, firstly you have to login all of the CNA node of FusionSphere which all the luns were maped to.
2. Run this command fdisk –l to list all the disks used in the OS and confirm the disk label which you want to delete mapping.
3. Please record the relationship between the disk label and disk path-based name, like [ /dev/sdX, /dev/disk/by-path/XXXX]
4. Remove the disk from the SCSI subsystems by command : echo 1 > /sys/block/device-name/device/delete, device name represent to the disk name, need to replace to the real word.
5. After you did that from all the hosts where those luns were maped, delete the luns from storage using dellun [ -force ] -lun lun id from CLI or directly from ISM, like below: