IBM i backups: SAVLIB, SAVOBJ, SAVSYS, save files, and the GO SAVE menu

Goal

Produce a verifiable backup of one or more IBM i libraries without an unattended job stalling on an operator prompt.

Prerequisites

• Enough authority to run save commands against the target libraries (object authority, and *SAVSYS special authority for SAVSYS or a full system save).
• A save device, or spare disk space for a save file if saving to disk instead of tape.
• For SAVSYS and GO SAVE options 21, 22, 23 and 40: a maintenance window, because they end all subsystems (restricted state), which also ends TCP/IP, SSH sessions and every user job.

Steps

1. To save to a save file instead of tape, create it first, in a library other than the one being saved: CRTSAVF FILE(otherlib/mysavf). IBM's own data-preparation guidance for diagnostic uploads uses exactly this pattern — create the save file, then save into it — before the resulting save file is compressed or transferred.
2. Save one library: SAVLIB LIB(mylib) DEV(*SAVF) SAVF(otherlib/mysavf). Save individual objects instead of a whole library with SAVOBJ OBJ(...) LIB(mylib) DEV(*SAVF) SAVF(...). Objects locked by active jobs are not saved unless save-while-active is requested (SAVACT). SAVSYS saves the operating system and security/configuration data; it runs only in restricted state and cannot write to a save file (tape or optical/virtual media only).
3. For a repeatable full or partial system save, use the GO SAVE menu rather than hand-built command sequences: option 21 saves the entire system, 22 saves system data only, 23 saves all user data, and 40 saves all libraries other than the system library. Start them from the system console (IBM's unattended-save procedure requires this for option 21), never from an SSH or pass-through session, which restricted state would end. On IBM i 7.1 and later these options were enhanced to gracefully end TCP/IP servers and host servers before ending subsystems to restricted state, rather than dropping active TCP/IP connections abruptly.
4. For an unattended run of GO SAVE options 21/22/23, pre-load the system reply list so the save does not stop waiting for a human to answer a prompt: add inquiry message CPA3708 (raised after CPF3777 reports libraries partially or not saved) with ADDRPYLE SEQNBR(nnnn) MSGID(CPA3708) RPY('G'), and set the job to use the reply list (CHGJOB INQMSGRPY(*SYSRPYL)), or answer Y to "Use system reply list" in option 20 on the Save menu so every future option 21/22/23 run uses it.
5. Verify: check the job log and any CPF3777 messages for the count of libraries saved versus partially saved versus not saved, and confirm expected libraries appear with DSPSAVF (for a save file) before deleting anything.

Expected result

A save file or tape whose completion messages show all target libraries fully saved, produced without an operator having to answer a message.

Limits and test basis

Menu option numbering and the unattended-save reply-list procedure are as documented by IBM Support for GO SAVE/GO RESTORE; confirm the exact message IDs your release generates before relying on the reply list alone in production. No experiment or measurement is claimed. Restoring is the mirror operation (RSTLIB/RSTOBJ/RSTUSRPRF and GO RESTORE); test a restore into a non-production environment before depending on a save.