It is a subsystem which allows arbitrary physical storage to be recognized as a virtual disk device.
WLM's actions in moving aliases from one disk device to another take a few seconds for the effects to be seen.
Thus, if the file contains an entire file system, the file may then be mounted as if it were a disk device.
This may be achieved by a simple NFS server, shared disk devices or even file replication.
Support for disk devices with large sector size (important for hardware RAID operation).
It included support for partitioning table rows in a database across individual disk devices, and "virtual columns" which are computed only when required.
Other (non IBM-compatible) systems may have different boot sector formats on their disk devices.
The usual hard disk devices used by the manufacturer were narrow or SCSI-1 5200rpm and 7200rpm drives.
The disk device is not to be used with a spacer.
An example for a ksmeta variable could be the name of a disk device in the system.