ARCMDEXT—Input Data Structure

The third word of Table 1 points to the address of the area that is described in Table 1.

Table 1. ARCMDEXT Input Data Structure
Offset	Length or Bit Pattern	Description
00 (X'00')	4	Approximate allocated size of the data set, in units of 1024 bytes. For multivolume data sets, this is the size of the data set across all volumes on which it resides. The size calculation is based on a 2KB blocking factor for any given DASD. The calculation gives only an estimate of the size. If your data sets use a blocking factor other than 2048 bytes, the space allocated for your data set might be larger or smaller than is needed.
04 (X'04')	8	Identifies the level of parameter list and data structure. If there is a value other than 'EXPAND1' at this offset, then this and subsequent fields are not part of the structure.
12 (X'0C')	2	First byte – input flags: 1... .... Data set is a candidate for reconnection. 0... .... Data set is not a candidate for reconnection. .1... .... Data set is being processed for extent reduction. .0.. .... Data set is not being processed for extent reduction. ..1. .... Interval migration is in progress. ..0. .... Interval migration is not in progress. ...1 .... Primary space management is in progress. ...0 .... Primary space management is not in progress. .... 1... The Days(0) parameter was specified on the MIGRATE command. .... 0... The Days(0) parameter was not specified on the MIGRATE command. .... .1.. The CONVERT parameter was specified on the MIGRATE command. .... .0.. The CONVERT parameter was not specified on the MIGRATE command. .... ..1. The migration eligibility age field at offset X'2E' in the input data structure is valid. .... ..0. The migration eligibility age field at offset X'2E' in the input data structure is not valid. .... ...1 Migration is a result of a migrate data set command. .... ...0 Migration is not a result of a migrate data set command. Second byte – input flags: 1... .... On-demand migration is in progress. 0... .... On-demand migration is not in progress. .xxx xxxx Reserved
14 (X'0E')	2	Length of management class name in the following field. If this field is zero, there is no associated management class.
16 (X'10')	30	Management class name associated with the data set.
46 (X'2E')	2	Number of days since the data set became eligible for migration. This field can contain a negative value if DAYS(0) is specified on the MIGRATE volume command for an SMS-managed volume and for SMS and non-SMS data sets being processed for extent reduction. In both cases, the negative value represents the number of days until the data set is eligible for migration, under the normal criteria.