The VM2000 disk configuration can also change during ongoing VM2000 operation, e.g. by adding new or reconfiguring existing disk devices. Therefore, checking and updating the VM2000 disk configuration may become necessary even after starting VM2000.
In the following cases, VM2000 automatically checks and updates the disk configuration of affected disk devices:
a dynamic I/O configuration modification (see section "Dynamic I/O configuration modification")
every exclusive assignment of a disk device to a VM or an assignment of a shareable disk device to the first VM using
/ADD-VM-DEVICESa request for the hardware data of a disk device by a guest system (for SHC-OSD), if the device is yet unknown in VM2000
In some cases, VM2000 is unable to check the disk configuration automatically.
The VM2000 administrator can manually check and update the VM2000 disk configuration with the /CHECK-VM-DISK-CONFIGURATION command.
In the following cases, it can be helpful to check and update the VM2000 disk configuration manually with /CHECK-VM-DISK-CONFIGURATION:
When VM2000 is started, there are already disk devices defined in the IOCF (IORSF) but not configured in the disk storage system. These disk devices can be configured in the disk storage system at a later point.
Free devices in the disk storage system have been reconfigured there and they have probably received different internal device numbers.
In both cases, /CHECK-VM-DISK-CONFIGURATION identifies the most recent hardware data and the PAV configuration of these disk devices and then updates the VM2000 disk configuration. These devices do not have to be assigned to a VM.
/CHECK-VM-DISK-CONFIGURATION initiates checking the VM2000 disk configuration (VMS4910 message). The VM2000 hypervisor checks the data of all generated disk devices and updates the data of the VM2000 disk configuration. The completion of the check is reported asynchronously to the VM2000 administrator and the console of the monitor system with the VMS4912 message.
In the above two cases, transfer of the correct hardware data to SHC-OSD is only ensured with /CHECK-VM-DISK-CONFIGURATION.