Introduction to FlashCopy

FlashCopy for IBM iFlashCopy for IBM i

Chuck LosinskiDirector of Automation Technology

Robot

Broadcasting live from Eden Prairie, Minnesota

Chuck StupcaIBM i ExpertIBM (retired)

FlashCopy for IBM iFlashCopy for IBM i

Agenda

• FlashCopy Defined

• How FlashCopy Works

• FlashCopy Options

• FlashCopy Space Efficiencies

• Automation Opportunities

What is FlashCopy?

• A function that occurs within a SAN storage device

• Provides a point-in-time copy of the contents of disk volumes

• Can be a full system or an IASP

• Many options for the copy process available

• Differences between V7000 and DS8000

Save While Active

Before starting a discussion of FlashCopy, let’s review a more familiarpoint-in-time copy: Save While Active

1.When a Save While Active is started, a sync point is reached beforethe save operation starts (this may take some time)

2.The objects to be saved are marked for processing by the save

3.Users may begin to use the objects being saved

4.If an object is changed, before it has been saved, the originalinformation is moved to a shadow area

5.When the save operation reaches the changed information,the original information is saved from the shadow area

FlashCopy Basics

• A FlashCopy takes place within a single storage unit—you cannot flashfrom one storage device to another

• FlashCopy is a physical copy of the disk unit—the storage unit has noconcept of objects

• Logical saves (SAVOBJ, SAVLIB, etc.) can be taken from the FlashCopy units

• There are many different options when you take a DS8000 FlashCopy

• A system or IASP may be quiesced in order to reach a sync point(usually a matter of seconds)—highly recommended

• Two basic forms of FlashCopy

– FlashCopy with copy

– FlashCopy no copy

FlashCopy with Copy

The contents of all disk units in the FlashCopy operation are copiedfrom source volumes to target volumes.

Source Volumes Target Volumes

FlashCopy with Copy

Force all changes from main storage to the source volumes and issue the FlashCopy command. A bitmap with all zeroes is generated by the DS.

000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

BitmapSource Volumes Target Volumes

FlashCopy with Copy

Each track is copied from the source volumes to the target volumes. As the tracks are copied, the corresponding bit in the mask is changed from 0 to 1.

111111111100000000000000000000000000000000000000000000000000000000000000000000000000000000


FlashCopy with Copy

Since both the source and target volumes are available for use, the bitmap directs users of the target volumes to the location of the information being used:

• 1 = use the target volume• 0 = use the source volume

111111111100000000000000000000000000000000000000000000000000000000000000000000000000000000


FlashCopy with Copy

Since the source volumes are in use, what happens when a track that hasn’t been copied is changed in the source volumes?

111111111100000000000000000000000000000000000000000000000000000000000000000000000000000000


FlashCopy with Copy

Before the change is written to the source volume, the original trackis copied to the target volume and the corresponding bit is set to 1.

111111111100000000000000000000000000000000001000000000000000000000000000000000000000000000


FlashCopy with Copy

Since the bit of the changed track is set to 1, the users of the target volumes know that the correct data is in the target—kind of like Save While Active knowing to use the shadow area.

111111111100000000000000000000000000000000001000000000000000000000000000000000000000000000


FlashCopy with Copy

Eventually, all tracks are copied from the source to the target. At this point, the default FlashCopy operation is complete and the bitmap is removed. There isno longer a relationship between the source and target volumes.

11111111111111111111111111111111111111111111111111111111111111111111111111111111


FlashCopy with Copy

Now you have a full copy of the original source volumes to use!


FlashCopy with Copy

What happens when a track that hasn’t been copied is changed in thetarget? The change is written to the target volume and the bit is set to 1.The track will not be copied from the source to the target.

111111111100000000000000000000000000000000001000000000000000000000000000000000000000000000


FlashCopy no Copy

Only the contents of changed tracks on disk units in the FlashCopy operation are copied from source volumes to target volumes.


FlashCopy no Copy

Force all changes from main storage to the source volumes and issue the FlashCopy command. A bitmap with all zeroes is generated by the DS.

000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000


FlashCopy no Copy

No background copy of source tracks to target tracks is performed.

000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000


FlashCopy no Copy

When a track in the source volumes is being changed, the track is copiedto the source, and the corresponding bit is set to 1.

000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000


FlashCopy no Copy

Only the original contents of changed tracks are moved to the targets.

000000000000100000000000000010000000000000010000000000000000000000000000001000000000000000


FlashCopy no Copy

Changes to the target system cause the copy bit to be set to 1. This will prevent a change to the source from overwriting the target change with original data.

000000000000100000000000000010000000000000010000000000000000000000000100001000000000000000


FlashCopy no Copy

• The relationship between the source and target remains in place untilall source tracks have been changed (highly unlikely).

• Usually the flash copy relationship is explicitly removed when the userhas finished using the targets.

• This form of FlashCopy is typically used to save objects on a partitionthat is different from the production partition.

• Since few of the tracks are likely to change during the save operation,there may be contention for access to the source volumes—usually the interference is not noticeable.

FlashCopy V7000

• Source and target volumes are specified using a mapping operation

• Target volumes must be identical in size to the source volumes

• Multiple volumes may be placed in a consistency group

– Similar to a DS FlashCopy of multiple volumes

– Provides a point-in-time copy for all volumes in the consistency group

• Rather than copying tracks, V7000 copies “grains”

– User specifies the size of a grain

– May be 64K – 256K

– Default is 256K

• FlashCopy on V7000 is with copy

Other DS8000 FlashCopy Options

• Persist: keep a FlashCopy relationship in place

• Record: keep track of changes made since the last point in time copy

– Often used in conjunction with the persist option

• Target inhibit: prevent writing to the target volumes

– Do not use with IBM i

Using Persist and Record

• Most often used to update target volumes copied using FlashCopy with copy

• At the completion of the full copy from source to target,the bitmap between source and target is retained

• Because record is also specified, a second bitmap is used to record the changes on the source volumes and target volumes

• At the next instance for FlashCopy, a variation calledResync flash is used

Resync Flash

• Changes to tracks in both sets of volumes are recorded in the bitmap• Remember that our original flash was a point-in-time flash of the

source volumes

001000000000100000000000000010000000010000010000000000000001000000000000001000001000000000


Resync Flash

In order to restore the changed tracks in the target to the values in the original FlashCopy, the changes will be “backed out” using the unchanged pages inthe source.

001000000000100000000000000010000000010000010000000000000001000000000000001000001000000000


Resync Flash

• Full copy of source volumes must be completed

• When a resync flash is issued, a second bitmap of all zeroesis created

• Changes that occur while the resync flash is taking place are recorded in the second bitmap

– Changes to a track in a source volume will cause the original track to be written to the target

– Changes to a track in a target volume are more complicated

Resync Flash—Changes to Target Volumes

Condition 1 – the track is not scheduled to be copied during the resync flash

•The change is made to the target volume and the corresponding bit in the change recording bitmap for the next resync is set to 1.

•The track will not be copied from the source volume to the target volume.

Condition 2 – the track is scheduled for resync and has already been copied from the source

•The track on the target is changed.

•The corresponding bit in the change recording bitmap for the next resync is set to 1.

Condition 3 – the track is scheduled for resync but has not yet been copied from the source

•The track on the target is changed and the corresponding bit in the change recording bitmapfor the next resync is set to 1.

•The track will not be copied from the source volume to the target volume.

Why Use FlashCopy

• Clone an IASP or system using FlashCopy with copy

• Use the target volumes for save operations– IPL the full system flash with special handling

• System name• IP addresses

– Vary on a FlashCopy IASP

• In the event that the source volumes become mucked,the target volumes provide a quick recovery to the pointin time of the FlashCopy

Saving Objects from a FlashCopy

• The save is taking place on a different system

• An IBM i has an operating system option for saving from a full system– The production system will not have the date of last save changed

– IBM i will adjust the catalog to “spoof” a save from the production system

• Saving from an IASP attached to a different partition is much easier– The save is still done on a different system/partition

– IBM i has an option to update the last saved information in the source IASP

• Lab Services Toolkit provides an automated process for both full system and IASP FlashCopy

Space Efficient FlashCopy

• To this point, the target volumes in either a DS8000 or a V7000 have been the same size as the source volumes (fully provisioned).

• Do we need fully provisioned targets?– FlashCopy no copy will not copy everything– Often times, target volumes have a short life span, e.g., they exist only until a

save operation is complete

• In a DS8000, we can use targets that are smaller than the source volumes (thin provisioning).


The DS8000 targets are configured differently.

Space is allocated for the target volumes.Allocated space is a percentage of the space for the source volumes.Choose a percentage that will not overflow during the save operation.

Source Volumes


“Virtual” target volumes are defined to be the same size as the source volumes.

There is a mapping between the tracks of the target volumes and the actual disk space used for the FlashCopy.




A change to a track in the source causes the original track to be written to the allocated area.

The bitmap between source and target indicates that the original page is in the “virtual” target disk.




When a user of the target volumes accesses the changed page, the bitmap directs the read to the target volume.

The changed track in the target volume is mapped to original information in the allocated area.



FlashCopy Summary

• Contained within a single storage unit

• A fast way to establish a point-in-time image of volumes(disk units) in IBM i

• Copies are physical, not logical i.e., there is no way to restore individual objects from a FlashCopy

• Can make full system or IASP copies

• Save operations can be performed on the target units

• Space efficient FlashCopy reduces storage requirements

Resources

• Redbooks– SG24-7938 Overview of the IBM Storwize V7000– SG24-8886 IBM System Storage DS8000: Architecture and Implementation– SG24-7120 IBM i and IBM System Storage– SG24-7103 IBM System Storage Copy Services and IBM i– SG24-6788 IBM System Storage DS8000 Copy Services for Open Systems

• IBM Education– AS541 IBM PowerHA for IBM i, Clustering, and IASP Implementation (4 days)– OS830 System Storage DS6000 and DS8000 on I (3 days)

• STG Lab Services – IASP Copy Services Toolkit (2 versions)– Full System FlashCopy Toolkit

Automation Opportunities

• Many of the Robot products can exploit this technology– Robot/SCHEDULE to automate the FlashCopy execution– Robot/SAVE to execute and track your backup to media– Robot/CONSOLE to monitor for FlashCopy messages– Robot/ALERT to notify you of any issues– Robot/SPACE to track disk usage statistics, notify of growth thresholds and

automate cleanup tasks

Automated Job Scheduling- Improve uptime- Eliminate errors - Avoid overtime- Save time with automated documentation- Event-based scheduling more effective

Performance Management- Dynamic expert tuning - Proactive disk saving- Capture runaway jobs fast- Managed impact of change- Easy to show that SLAs have been met

Message Management- View only important messages- Acknowledge important messages- Single pane of glass view- Maximize uptime - Easy to locate cause of errors

Disaster Recovery- Automate save and restore- Flexible tape management - Reliable, unattended backups- Powerful data security and audit - Simplified disaster recovery planning

Robot systems management solutions save money and help improve competitiveness.

Automation Opportunities

Robot/SCHEDULE, Enterprise, and Replay

Event-driven scheduling | Flexibility to react to changing events

Schedule Activity Monitor | Powerful scheduling dashboard

Replay | Automates interactive green-screen tasks

Cross Partition Dependencies | Add Robot/NETWORK

Cross Platform Dependencies | Add Robot/SCHEDULE Enterprise

Sophisticated calendars | Adapt to any schedule or fiscal year

Dynamic parameters | Support unattended job submission

Good Morning Report | Keeps you posted on nightly activity

Job blueprints | Generate graphical views of job flow

Database | All data and schedules are stored on the IBM i

Job Blueprint shows you job dependencies between jobs, partitions and platforms!

The world’s most advanced job scheduler for IBM i.

Robot Plug-In Modules: Robot/SCHEDULE SAP Interface • Robot/SCHEDULE Oracle E1 Interface • Robot/REPLAY • Robot/NETWORK

Event-Driven Job Scheduling for IBM i and Windows, Unix, Linux and Interactive Tasks

ROBO

T/SCHED

ULE

ROBO

T/SCHED

ULE

Related Robot products: Robot/ALERT and Robot/NETWORK

Robot/CONSOLE and Robot/ALERTSystem Message and Resource Management

Message management | Handle messages automatically

Message notification | Escalate only important messages

OPAL | Defines complex message processing

SNMP SMS SMTP 2-way | Add Robot/ALERT

Consolidated monitoring | Add Robot/NETWORK

Resource monitoring | Keep resources healthy

System log monitoring | Maintain security and compliance

Message history | Detailed historical message analysis

Good Morning Report | Keeps you posted on nightly activity

Powerful interface | Easy to use

Message set creation wizard | Easy to install

Automate message responses and resource monitoring such as: CPU, subsystem, line, job queue, and output

queue. Escalate only the exceptions and reply remotely.

Automated system monitoring. Don’t be tied to your screen.

ROBO

T/CON

SOLE

ROBO

T/CON

SOLE

Robot/SAVE

Automated backup | Eliminate save errors

IFS groups | Easily manage IFS backups and restores

Data encryption | Secure mission critical data

Save media management | Error-free media handling

Data centre management | Multi-system/data centre support

Centralized scratch pool | Reuse media across multiple systems

Guided restoration | Improves Recovery Time Objective (RTO)

Object archive | Easy to restore prior versions of data/objects

Restricted State Utility | Safe, unattended system-level saves

Ad hoc operations | Management of media outside of DR

Reports | Comprehensive DR documentation suitable for audit

Move Sets help manage the location of save media at all times.

Disaster Recovery

ROBO

T/SAVERO

BOT/SAVE

Related Robot products: Robot/SCHEDULE • Robot/ALERT • Robot/NETWORK

It’s more than save and restore, it’s a whole DR solution.

Robot/SPACE

Critical Storage Investigator | Identify storage problem causes

Collection explorer | Graphical storage statistics and trends

Storage audits | Automated disk cleanup

ASP monitors | Monitor ASPs individually

Active job storage monitoring | Identify out of control jobs fast

Storage collections | Flexible, user-defined statistical groupings

Robot/QUERY | Flexible, user-defined storage analysis

Reports | Assist in monitoring storage spaceCritical Storage Investigator (CSI) allows easy

identification of storage problems.

Proactive Storage Management

ROBO

T/SPACERO

BOT/SPACE

Related Robot products: Robot/SCHEDULE • Robot/ALERT • Robot/NETWORK

Save disk space. Predict future space requirements. Avoid critical storage conditions.

Questions?

PRESENTATION RECAP:

• FlashCopy Defined

• How FlashCopy Works

• FlashCopy Options– With and without copy– Resync flash– Persist and record– Running saves

• FlashCopy Space Efficiencies

• Robot automation opportunities

Thank you for joining us today!

Telephone: 800-328-1000 sales 952-933-0609 support

Website: www.helpsystems.com

Presenters: [email protected] | 952-563-2790 [email protected]

Contact Information

Chuck LosinskiDirector of Automation

Technology, Robot

Chuck StupcaIBM i ExpertIBM (retired)

Introduction to FlashCopy

Technology

Transcript of Introduction to FlashCopy