I'm considering implementing VSAM KSDS compression using SMS. I came across APAR II14507 that indicates that REPRO will copy from a compressed to a compressed KSDS without any decompress / compress occurring. (See message IDC0038I COMPRESSION INTERFACE USED, DATA TRANSFER COMPLETE). However, there are requirements like the same CI size, etc AND, at the end of the REPRO, IDCAMS is unable to provide a record count. The same CI size and no record count seems to indicate that IDCAMS is not going through normal load processing. That causes me to think that it might not be re-distributing freespace. Can anyone confirm whether that is true or not. There's a major lack of information available on this comperssion interface.