On Fri, 29 Aug 2014 22:18:46 -0500, Bill Godfrey <[email protected]> wrote:
>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. Self-correction: actually you requested space for 0 blocks, but when data was written it used the secondary allocation of 300 blocks to create the first extent. >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
