Example In the following example, volume SRC101 and SRC102
reside on LSS 01. Volume SRC203 resides on LSS 02. LSS01 and LSS02
can be in the same or different storage control units. SRC101 is selected
as the verification volume.
- The first COPY command -- by
default, in SERIAL mode -- will copy
the verification volume, SRC101.
- When the first COPY command
completes, the PARALLEL command instructs
DFSMSdss to switch to parallel mode. DFSMSdss will execute all subsequent
commands in parallel until it reaches the SERIAL command which tells
DFSMSdss to wait for all previous commands to finish before proceeding.
- The user instructs DFSMSdss to verify the state of the FlashCopy® Consistency Group
using the specified verification volume during the "thaw" operation.
The CGCREATED command should always be issued to thaw the
volumes whether the copy commands completed successfully or not. In
other words, the control statements do not need to check condition
code prior to the CGCREATED command.
//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)
/*
Note: - The freeze and thaw operations require
the specified devices support
the FlashCopy Consistency
Group function.
- There is one Consistency Group timer per logical
subsystem (LSS)
for FlashCopy.
- The
Consistency Group timer has a default of 120 seconds. The
timer value can be set via the ESS Web User Interface.
- The CGCREATED operation
is processed at LSS level. It
thaws all the volumes currently in "frozen for consistency grouping"
state in the LSS that received the command. When a "thaw" command
is received by an LSS that does not have any frozen volumes in a FlashCopy Consistency Group,
the command is accepted, but no actual processing takes place.
- Multiple FlashCopy Consistency
Groups with volumes in the same LSS must not be formed at the same
time.
- When a FlashCopy Consistency
Group timer expires before the "thaw" command is received on the LSS,
I/O activity will be allowed to resume on all currently frozen volumes
in the LSS. As a result, the copies of the volumes are likely inconsistent.
- When FCCGFREEZE is specified, if the FlashCopy pair failed to be established,
DFSMSdss will withdraw all FlashCopy relations
previously established with FCNOCOPY FCCGFREEZE option by the same
DFSMSdss invocation. DFSMSdss will also stop processing the rest of
the COPY FCCGFREEZE commands issued by the same invocation (e.g.,
in the same job step).
- During a CGCREATED operation,
or a FCFREEZE operation
that ends in error, DFSMSdss might issue a FlashCopy withdraw request for the source
and target volume. If either volume is attached at device address X'0000',
the system fails the FlashCopy withdraw
operation with warning message ADR815W. Processing continues.
For more information, about using the FCCGFREEZE keyword on the
COPY command, refer toFCCGFREEZE.
For more information about the ACCESSVOLUME and FCCGVERIFY keywords
on the CGCREATED command, refer to ACCESSVOLUME and FCCGVERIFY.
For more information
about FlashCopy Consistency
Groups, refer toz/OS DFSMS Advanced Copy Services.