z/OS V1R6.0 DFSMS Access Method Services for Catalogs

DCOLLECT Outputmajority of I/O scheduled for the data sets in this Storage Class isfor READ, WRITE or unknown. This field is also mapped byDSCBIADC, DSCBIARD, and DSCBIAWR.0 Sequential access bias is unknown.1 Sequential access has read bias.2 Sequential access has write bias.DSCACCESDSCIACDLDSCDIRRDSCSEQRDSCSTSDRDSCCCHSTDSCDIRCWDSCSEQCWDSCPAVThis field specifies whether the data sets in this storage classshould be allocated to volumes supported by concurrent copy.When used with the ABACKUP/BACKUP COPY TECHNIQUEattributes of the management class, this field determines if the datasets should retain continuous write access during backup.0 Continuous Preferred - The data set should beallocated to volumes supported by concurrentcopy. If this cannot be done, a data set can beallocated to volumes that do not supportconcurrent copy.1 Continuous - The data set must be allocated tovolumes supported by concurrent copy. Theallocation is unsuccessful for data sets that cannotbe allocated to such volumes.2 Standard - The data set should be allocated tovolumes that do not support concurrent copy. Ifthis cannot be done, a data set can be allocated tovolumes that support concurrent copy.3 Nopref - The data set is allocated to volumeswhether or not the volumes are concurrent copycapable.This field indicates the time required (in seconds) to locate, mount,and prepare media for data transfer.This field shows the direct access response time required for datasets in this storage class. The value is the number of millisecondsrequired to read or write a 4-kilobyte block of data.This field shows the sequential access response time required fordata sets in this storage class. The value is the number ofmilliseconds required to read or write a 4-kilobyte block of data.This field shows the sustained data transfer rate for data sets inthis storage class. The system uses this value to determine thenumber of stripes it will try to allocate for the data set.Cache set name, comprised of two parts - DSCCSLEN (length offollowing name), and DSCSNAMDirect CF weightSequential CF weightPAV value specified for use in the volume selection processvvv0 - The PAV status of the volume is not considered in thevolume selection algorithm1 - Volumes with no PAV capability are preferred over volumeswith PAV capability (Standard)2 - Volumes with PAV capability are preferred over volumeswithout PAV capability (Preferred)Appendix F. Interpreting DCOLLECT Output 483