If SYSUT1 and SYSUT2 define the same partitioned data set or PDSE, new extents resulting from updates on SYSUT2 are not retrievable in SYSUT1.

The input and output data sets contain blocked or unblocked logical records with record lengths of up to 80 bytes. The input and output data sets may have different block sizes as long as they are multiples of the logical record length. However, if insufficient space is allocated for reblocked records, the update request is ended.

If an ADD operation is specified with PARM=NEW in the EXEC statement, the SYSUT1 DD statement need not be coded.

If the SYSUT1 DD statement defines a sequential data set on tape, the file sequence number of that data set must be included in the LABEL keyword (unless the data set is the first or only data set on the volume).

If the output data set (SYSUT2) does not already exist and is to reside on a direct access device, space must be allocated for it. The SYSUT2 DD statement must not specify a DUMMY data set.

When adding a member to an existing partitioned data set or PDSE using an ADD function statement, any DCB parameters specified on the SYSUT1 and SYSUT2 DD statements (or the SYSUT2 DD statement if that is the only one specified) must be the same as the DCB parameters already existing for the data set.

If an UPDATE=INPLACE operation is specified, the SYSUT2 DD statement should not be coded.

If both the SYSUT1 and SYSUT2 DD statements specify standard user labels (SUL), IEBUPDTE copies user labels from SYSUT1 to SYSUT2.

If the SYSUT1 and SYSUT2 DD statements define the same partitioned data set or PDSE, the old master data set can be updated without creating a new master data set; in this case, a copy of the updated member or members is written within the extent of the space originally allocated to the old master data set. Subsequent referrals to the updated members will point to the newly written members. The member names themselves should not appear on the DD statements; they should be referred to only through IEBUPDTE control statements. The old directory entry for each member is not copied.

Related reading: For more information, see EXEC Statement.