Transcript Slide 1

Advanced Technical Support (ATS) Americas
What is FlashCopy?
Types of FlashCopy in System z
FlashCopy® is an “instant” T0 (Time 0) copy where the
source and target volumes are immediately available
for processing with full r/w access after the relationship
has been established. It is a hardware solution that is
software invoked. FlashCopy can be invoked by
DFSMSdss, TSO, ICKDSF, z/OS API, DS CLI, and the
DS Storage Manager (GUI). Open environments
typically use DS CLI or TPC for replication.
The following commands are shown in the following
order. First for DFSMSdss, then TSO, and finally
ICKDSF. Only DFSMSdss serializes resources.
The FlashCopy source is a set of tracks that can
consist of an entire volume or just a selected set of
tracks.
Full volume COPY and NOCOPY
Data on the entire volume is available for r/w on both
the source and target. COPY will physically copy all
source tracks to target and NOCOPY will only
physically copy updated tracks on source.
COPY FULL INDD(DASD1) OUTDD(DASD2) ADMIN DUMPCONDITIONING
 Request copy from source to target
•FlashCopy relationship created
COPY FULL INDD(DASD1) OUTDD(DASD2) FCNOCOPY ADMIN DUMPCONDITIONING
Target available for r/w
BACKGROUND COPY/NOCOPY
•Tracks copied from source to target
•COPY copies all tracks
•NOCOPY copies tracks updated on source
•Attempts to r/w data already copied
FCESTABL SDEVN(X’uadd’) TDEVN(X’uadd’)
FCESTABL SDEVN(X’uadd’) TDEVN(X’uadd’)
MODE(NOCOPY)
•Read/write to volume I/O is issued to
FLASHCPY ESTABLISH DDNAME(ddname) –
TARGETVOL(lss,cca,cuuu)
•Attempts to read a target track not already
copied obtains data from source
FLASHCPY ESTABLISH DDNAME(ddname) TARGETVOL(lss,cca,cuuu) MODE(NOCOPY)
•Attempts to write a source track not already
copied is intercepted and source track copied to
target before update occurs
Note: BACKGROUND COPY will physically copy all
tracks from source to target while NOCOPY will only
physically copy tracks that are updated on the source.
Reads
source
target
Data set FlashCopy
Only for z/OS™ using DFSMSdss.
Writes
• What is FlashCopy?
• Types of FlashCopy in System z™
• Invoking FlashCopy functions
Although it is a remove flash command, the
relationship is maintained and starts the
BACKGROUND COPY.
• Which tool can invoke which
function
COPY FULL INDD(DASD1) OUTDD(DASD2) FCNOCOPYTOCOPY
• FlashCopy source and target
placement
FCESTABL SDEVN(X’uadd’) TDEVN(X’uadd’) FCNOCOPYTOCOPY
A persistent relationship is maintained even after the
BACKGROUND COPY completes otherwise it would
be withdrawn. To remove a persistent relationship,
manually withdraw it.
target
This document covers:
Background NOCOPY to COPY
Persistent FlashCopy
source
DS6000/DS8000
FlashCopy
in z/OS
Environments
Quick Reference
There is no single persistent parameter when
invoking FlashCopy in a System z environment. But,
persistent is used automatically when establishing an
Incremental FlashCopy or Fast Reverse Restore
Enabled (Global Mirror) FlashCopy.
March 2007
© International Business Machines Corporation, 2007. IBM,
and FlashCopy are registered trademarks and System z,
z/OS, DS6000, and DS8000 are of International Business
Machines in the U.S. and other countries. Other company,
product, or service names may be trademarks or service
marks of others. IBM reserves the right to change
specifications or other product information without notice.
This publication may include typographic errors and
technical inaccuracies. The content is provided as is,
without express or implied warranties of any kind, including
the implied warranties of merchantability or fitness for a
particular purpose.
© 2007 IBM Corporation
Advanced Technical Support (ATS) Americas
Types of FlashCopy in System z
 Multiple relationships
 Fast Reverse Restore enabled FlashCopy
 Consistency group FlashCopy
A single source volume can have up to 12 targets, of
which only one can be incremental.
Typically used in a Global Mirror environment.
 Incremental FlashCopy
FCESTABL SDEVN(ssss) TDEVN(tttt) MODE(ASYNC)
Incremental FlashCopy provides the capability to only
BACKGROUND COPY tracks that have been
changed since the last increment was taken. An
incremental flash can be performed in either direction.
Initial establish:
FLASHCPY ESTABLISH UNIT(ccuu) TARGETVOL(lss,cca,cuuu) CHANGERECORDING(YES) MODE(NOCOPY) INHIBITTARGETWRITES(YES)
Once a pair is established, extended long busy is
returned to the server when writes are issued
preserving the order of dependent writes. The
freeze lasts 2 minutes or until the unfreeze
command is issued.
 Fast Reverse Restore
COPY FULL INDYNAM(VOL00A)
OUTDYNAM(VOL00B) DUMPCONDITIONING ADMIN FCINCREMENTAL
Used to Global Mirror journal back to the Global mirror
secondary. Switch the original source and target
addresses
FCESTABL SDEVN(X’uadd’) TDEVN(X’uadd’) –
INCREMENTAL(YES)
FCESTABL SDEVN(ssss) TDEVN(tttt) ACTION(FRR)
FLASHCPY ESTABLISH UNIT(F001) –
TGTVOL(X’07’,X’01’,F701) –
CHANGERECORDING(YES)
FLASHCPY ESTABLISH UNIT(ccuu) TARGETVOL(lss,cca,cuuu) FASTREVERSERESTORE TGTOKPRIME(YES)
To reverse the increment, swap the swap the source
and target. To make sure you going in the correct
direction using DFSMSdss, specify
FCINCRVERIFY(REVERSE).
COPY FULL INDYNAM(VOL00B)
OUTDYNAM(VOL00A) DUMPCONDITIONING ADMIN FCINCREMENTAL –
FCINCRVERIFY(REVERSE)
Unit is the original target and TARGETVOL is the
original source.
FCESTABL DEVN(X’uadd’) SDEVN(X’uadd’) TDEVN(X’uadd’) ACTION(THAW)
Which tools invoke which FlashCopy Function?
API
DSF
DS CLI
Full volume
Yes
Yes
Yes
Yes
Yes
NOCOPYCOPY
Yes
Yes
Yes
Yes
Yes
When FCINCREMENTAL, INCREMENTAL, or
CHANGERECORDING is specified, persistence is
automatically set.
Incremental
Yes
Yes
Yes
Yes
Yes
CG
Yes
Yes
Yes
No
Yes
To maintain the incremental relationship, specify
recording on each
Persistent
only
No
No
No
No
Yes
Inband
Yes
Yes
Yes
No
Yes
FRR Enabled
No
Yes
Yes
Yes
Yes
FRR
No
Yes
Yes
Yes
Yes
Multiple
relations
Yes
Yes
Yes
Yes
Yes
Data Set
Yes
No
No
No
No
FCESTABL DEVN(devno) SOURCE(serialno lss
cca|lun) TARGET(serialno lss cca|lun)
MODE(COPY) SSID(ssid) REMOTE(YES)
FLASHCPY ESTABLISH UNIT(ccuu) SOURCEVOL(lss,cca,ser#,ccuu)
COPY FULL INDYNAM(SRC102) OUTDYNAM(TGT102) ADMIN DUMPDOND FCCGFREEZE
FCESTABL SDEVN(X’uadd’) TDEVN(X’uadd’) –
ACTION(FREEZE)
TSO
 Inband FlashCopy
Inband FlashCopy allows FlashCopy requests to be
issued remotely through an existing PPRC link.
COPY FULL INDYNAM(SRC101) OUTDYNAM(TGT101) ADMIN DUMPCOND FCCGFREEZE
CGCREATE FCCGVFY(SRC101)
ACCVOL(SRC101)
DSS
COPY FULL INDYNAM(VOL00B) OUTDYNAM(VOL00A) DUMPCONDITIONING ADMIN FCINCREMENTAL –
FCINCRVERIFY(REVERSE)
FlashCopy Consistency Groups provides a
mechanism for achieving consistent data copy
across multiple volumes and disk subsystems
without requiring that application I/O be quiesced.
Must use the DEVN parameter on the TSO THAW
command. ICKDSF does not support consistency
group. Freeze is a volume level command and the
THAW command is a LSS level command. Before
issuing thaw, make sure that there are no other
consistency groups being formed in that LSS.
FlashCopy source and target placement
Same
Cluster
Same
DA
Same
Rank
FlashCopy
Establish
Performance
Same
Doesn’t
matter
No
Background
Copy
Performance
Same
Different
No
FlashCopy
impact to
Application
Same
Doesn’t
matter
No
© 2007 IBM Corporation