Hi Radoslaw, I’ll try to provide some clarity to the example.
1. When attempting to establish your consistency group, you want to perform the CGCREATED command on the first established device of your group. The example allows the first volume to be established and finish, prior to establishing the rest of the volumes of the consistency group in parallel. Had you performed all of those devices in parallel (as you suggest), there is no guarantee that DSS would have executed and therefore established the first volume of your list in order. Allowing the first to be done in serial ensures you check the correct device. 2. FCCGFREEZE keyword indeed tells the device to be in a busy state. Therefore ensuring your consistency group is resumed (thawed) at the same time as all your devices in the group. 3. The CGCREATED command works at the LSS level. The command will verify that your first device (FCCGVFY) is in the correct state – ensuring that all your devices in the group are consistent. If you notice, the sample describes that SRC101 and SRC102 are in LSS1, and SRC203 is in LSS2. The ACCESSVOLUME is simply a single device in each LSS that is part of your consistency group. The example could also have been specified as ACCVOL(SRC102,SRC203)…as the result is the same. It is not necessary to specify all volumes you specified, only that each LSS is reachable. I hope this helps. Please let me know if I can provide further clarification. Ernesto E. Figueroa DFSMSdss Product Owner From: IBM Mainframe Discussion List <[email protected]> on behalf of Radoslaw Skorupka <[email protected]> Date: Sunday, November 3, 2024 at 3:28 AM To: [email protected] <[email protected]> Subject: [EXTERNAL] Re: Flashcopy consistent clone W dniu 31.10.2024 o 16:11, Glenn Wilcock pisze: > Here is an example of using DSS to create a FlashCopy consistent clone. Note > that for active data, this is considered a 'crash consistent' copy because > the consistency is at a physical i/o level, not a logical transaction level. > > https://www.ibm.com/docs/en/zos/3.1.0?topic=group-example (DFSMSdss Storage > Administration, 'Backing Up Volumes with FlashCopy consistency group')e > message: INFO IBM-MAIN Thank you for the hint. Actually I saw the example, but I don't understand it. |//SYSIN COPY FULL INDYNAM(SRC101) OUTDYNAM(TGT101) ADMIN DUMPCOND FCFREEZE PARALLEL COPY FULL INDYNAM(SRC102) OUTDYNAM(TGT102) ADMIN DUMPCOND FCFREEZE COPY FULL INDYNAM(SRC203) OUTDYNAM(TGT203) ADMIN DUMPCOND FCFREEZE SERIAL CGCREATED FCCGVFY(SRC101) ACCVOL(SRC101,SRC203) /*| I don't understand why the PARALLEL is not the first command. I think all three COPY command should be performed in parallel. I guess FCFREEZE means "wait until..." Then SERIAL - that's OK as far as I understand. Then CGCREATED - I understand it as "start a copy of consistency group". However I don't see SRC102 in the command. Is it a typo in ACCVOL()? Regards -- Radoslaw Skorupka Lodz, Poland ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
