z/VSE's Storage Options
Ingolf24 120000DRN3 Visits (5822)
Today I will discuss z/VSE's disk storage options.
z/VSE supports 3 disk architectures: (Extended) Count Key Data (ECKD), Fixed Block Architecture and Small Computer System Interface (SCSI).
ECKD is supported by e.g. the IBM System Storage DS8000 series. DS8870 is the latest ECKD device you can use with z/VSE. Most of our customers are using ECKD disks. z/VSE supports ECKD features such as Parallel Access Volume (PAV) and Flashcopy..
FBA support may be used on z/VM as virtual FBA minidisks or as FBA-SCSI disks.
Applications can access SCSI disk via FBA channel programs or FBA interfaces. . FBA channel programs are translated at low level I/O interfaces to SCSI commands. Disks like IBM System Storage DS8870, IBM Storwize V7000 or IBM XIV support the SCSI architecture. z/VSE's SCSI support is transparent to FBA and device independent applications.
If you want to migrate from ECKD to SCSI devices please consider that you can not Fast Service Upgrade (FSU) to a SCSI device (FSU only works from ECKD to ECKD or SCSI to SCSI). If your applications is not written device independent, you need to adapt them. The same is true for Job Control statements, e.g. EXTENT information needs to be changed from tracks to blocks.
Please contact me, if you want to have more information.