XenServer import ovf virtual machine failure, how to solve-CodePudding

The 2020-07-27 15:40:46, 130 ERROR XenOvfTransport. ISCSI [15] - Failed to start Transfer the VM. There was a pool_raise_if_allocation_failure is communicating with the plugin.
The 2020-07-27 15:40:46, 130 ERROR XenOvfTransport. Import [15] - Failed to Import a virtual disk over iSCSI. Failed to start Transfer the VM.
The 2020-07-27 15:40:46, 133 INFO XenAPI. Session [15] - Invoking xml-rpc method Session. Get_this_host
The 2020-07-27 15:40:46, 136 ERROR XenOvfTransport. Import [15] - Failed to Import.
The 2020-07-27 15:40:46, 136 ERROR XenOvfTransport. Import [15] - Failed to add the resource Hard Disk Image. Failed to Import.
The 2020-07-27 15:40:46, 136 ERROR XenOvfTransport. Import [15] - Failed to Import virtual disk from the file CentOS_8. 1 - disk1. VMDK to storage repository of 57880057-6883 - f79d - a14c - c939719e80d2.
The 2020-07-27 15:40:46, 136 INFO XenAPI. Session [15] - Invoking xml-rpc method VM. Destroy
The 2020-07-27 15:40:46, 190 ERROR XenOvfTransport. Import [15] - Failed to Import.
The 2020-07-27 15:40:46, 190 ERROR XenAdmin. Actions. AsyncAction [15] -
System. Exception: Failed to import.
-- -> System. IO. InvalidDataException: Failed to add the resource Hard Disk Image.
-- -> System. Exception: Failed to import.
-- -> System. Exception: Failed to import the virtual disk file.
-- -> System. Exception: Failed to import a virtual disk over iSCSI.
-- -> System. Exception: Failed to start Transfer VM.
-- -> XenAPI. Failure: There was a pool_raise_if_allocation_failure is communicating with the plugin.