Virtual Volume compression lets you compress data written to Virtual Volumes in the DASD buffer pool. When Externalized to physical tape or Recycled, compressed Virtual Volumes are not decompressed. Compressed volumes occupy less DASD and physical cartridge usage. This results in better DASD buffer and physical cartridge utilization. Increased virtual cartridge capacity also allows a CA Vtape subsystem to manage more user data in the DASD buffer. Compressed data requires fewer I/Os to read or write at the expense of additional CPU overhead needed to perform the actual compression or expansion of that data.
Virtual Volume Compression is activated and controlled through attributes defined in the Dynamic Options Section of the VTPARMS member of parmlib. The following parmlib attributes control how and when compression is activated:
|
Copyright © 2013 CA Technologies.
All rights reserved.
|
|