Do you use z/VSE virtual disks for temporary data ?
Ingolf24 120000DRN3 Visits (4315)
z/VSE has virtual disk support for a long time. I still see z/VSE installations, that don't use virtual disks, but could benefit from them.
With the virtual disk it is possible to have (temporary) data reside in virtual storage (in a data space) and not on a real disk device. Each virtual disk resides in its own separate data space. A virtual disk in z/VSE has been implemented by emulating a FBA (Fixed Block Architecture) disk device. You can use it like a real FBA device, without being required to change code in your applications. In addition, applications running in different partitions on the same z/VSE system can share virtual disks like real disk devices. However, you can not place a lock file on a virtual disk, because it is only known to the same system, where it is allocated. You can not share it with other z/VSE systems.
You can define up to 128 virtual disks in z/VSE.
Data on virtual disks can be accessed at memory speed. That is I/O intensive jobs and transaction see improved throughput and response times. Virtual disks are ideal for read only data. You may use virtual disks for temporary data, which can easily be recovered in case of normal or abnormal shutdown, e.g.
z/VSE Virtual disks can not be used for the IUI control file, hardcopy file, system history file, page data sets, CSD file, VSAM master catalog, ...
Performance consideration: Virtual disks in data spaces are subject to the same paging rules as virtual storage for address spaces. To benefit from virtual disks, you must have sufficient real (processor) storage available to avoid a possible paging bottleneck. If the real storage available is insufficient, I/O requests to real disks are replaced by I/O requests to the page data set.
For more information on virtual disks see the z/VSE Planning book. Our documentation is here.