On Fri, 29 Aug 2014 17:47:03 -0500, Paul Gilmartin wrote: >My command was (after deleting the output data set): > > _UNIX03=NO cp -B -P'SPACE=(10000,(0,300)),BLKSIZE=0' /dev/fd/0 > //TEMP.CBT854.ZIP > >ISPF DSLIST Information tells me: > > Data Set Information > >Data Set Name . . . . : user.TEMP.CBT854.ZIP > >General Data Current Allocation > Management class . . : **None** Allocated blocks . : 240 > Storage class . . . : **None** Allocated extents . : 2 > Volume serial . . . : 000000 > Device type . . . . : 3390 > Data class . . . . . : **None** > Organization . . . : PS Current Utilization > Record format . . . : VB Used blocks . . . . : 211 > Record length . . . : 1028 Used extents . . . : 2 > Block size . . . . : 27998 > 1st extent blocks . : 120 > Secondary blocks . : 300 Dates > Data set name type : Creation date . . . : 2014/08/29 > SMS Compressible. . : NO Referenced date . . : 2014/08/29 > Expiration date . . : ***None*** > >OK. I understand the "27998". That's SDB doing what it should. > >Where does the "120" come from? Where does the "240" come from? How >is the "10000" I coded reflected in the Info display? Did the C RTL >second guess me? Is this the 3390-pretending-to-be-a-3380? Does Info >show that if so? Are the Primary, Secondary, Allocated, and Used >in units of 10000 or 27998 or other? How can I tell? > >I can never get my head around this stuff. >
1st extent blocks, allocated blocks, and used blocks are all in units of 27998. Secondary blocks are in units of 10000. This value is kept in the DS1SCXTV field of the Format 1 DSCB, but is not shown by ISPF. The LISTDS command with the LABEL keyword will show the DSCB in hex, and the last 4 hex digits of the 14-digit value (there is only one that is 14 digits long) would be hex 2710 for 10000, preceded by a hex 80. You requested space for 300 blocks of size 10000 bytes. A track holds 5 blocks of size 10000, so you got 300/5 or 60 tracks as your first extent. ISPF DSLIST computed "1st extent blocks" as the number of 27998-byte blocks in the first extent. At 2 blocks per track, that is 120 blocks. More than 120 blocks were written, and a second extent was created, so "Allocated blocks" is 240 and "Used blocks" is 211. Bill ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
