CD-ROM device is no longer accessible after installing the Hyper-V Linux Integration Services

CAUSE：
This issue occurs because the Hyper-V Linux Integration Services unloads the ata_piix driver in order to provide an optimized IDE driver (hv_blkvsc) for the root file system. To get access to the CD-ROM device, the Linux Integration Services must be uninstalled.

WORKAROUND：
To work around this issue, mount the ISO in the virtual machine. To mount an ISO file in the virtual machine, the following command must be run before executing the mount command:

# insmod /lib/modules/$(uname -r)/kernel/drivers/ata/ata_piix.ko

Alternatively, copy the ISO file into the virtual machine and mount it using the -o loop option.