IBM DATA MIGRATION SERVICES - User manual

IBM Global Technology Services
December 2007
Storage migrations made simple.
Overcoming the challenges of technology refresh

Contents
2 Executive summary
4 Introduction
6 Data migration software
10 Technology refresh examples
28 Summary
Executive summary
Minimizing the impact of data migrations on business operations is a critical
part of the data center manager’s job. Studies have shown that technology
refresh—dened as replacing an older server or storage array with a new
one—is the primary driver of data migration. Storage hardware and server
replacement, as well as the expiration of storage equipment leases, means that
storage managers have to move data on a regular basis. Moving data for tech-
nology refresh can be problematic, however, due to application availability
requirements, incompatibilities between source and target systems, and time
and budget constraints. While technology refresh projects are typically sched-
uled to be performed during off-hours, today’s 24x7 environment means that
applications need to stay online, even during off-hours.
New software allows nondisruptive migration, meaning that applications
remain online during migration, without signicant performance delays. And
reliable methodologies that help plan, migrate and validate data migrations
can enable customization, speed the process and ensure data integrity—simplify-
ing the technology refresh process.
Storage migrations made simple.
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The following table presents ve key factors that show how data migration
software can simplify technology refresh and how Softek™ Transparent Data
Migration Facility (TDMF™) technology can meet these needs.
Key factors Description Softek TDMF capability
Performance Performance measurements
must take into consideration
how quickly data is copied
from the source to target,
and balanced against
network bandwidth and
system overhead.
TDMF software includes a throttling
or pacing capability that can speed
up or slow down data movement
depending on system demands in
order to easily balance migration.
Roll-back capability If something goes wrong, the
migration can be terminated
and restarted or application
processing can continue on
the source data/device.
Roll back can easily be accom-
plished with TDMF software,
although it can be problematic
with some other technologies,
such as volume managers.
Increase in
volume size
In a recent survey, 40 per-
cent of migrations involved
an increase in volume size
from the source to the target.
TDMF software can accommo-
date an increase in volume size.
Heterogeneous
source and
target hardware
While host-based prod-
ucts support unlike storage
devices, most array-based
products require that the
source and target come
from the same vendor.
TDMF software is hardware
independent.
Application downtime Applications have different
levels of business criticality
and therefore have varying
degrees of acceptable
downtime.
TDMF software allows for
nondisruptive data migration so
applications can stay online
and continue to process data
throughout the migration process.
Storage migrations made simple.
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Technology refresh is the primary
driver of data migration.
Highlights

Storage migrations made simple.
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Introduction
What drives data migration? In a recent Softek survey, technology refresh was
cited as the major reason for moving data. Technology refresh is dened as
replacing an array with a new one and most commonly occurs when:
• Theleaseonapieceofstorageequipmentends
• Dataisbeingmovedfromoldtonewstorage
• Thestoragesystemisbeingupgraded
• Theorganizationhasdecidedtostandardizeonaparticulartechnology.
Typically, most data centers lease their storage hardware under three-year agree-
ments. Once the agreement ends, the hardware needs to be replaced and the data
stored on it moved to new equipment. Data migration must be completed before
the lease expires to avoid additional monthly lease costs. In cases in which storage
hardware is purchased rather than leased, older arrays that are fully depreciated
can be expensive to maintain. Once again, purchase and implementation of new
equipment requires migrating data from the older arrays.
IT organizations justify purchase or lease of new equipment by the fact that
it is less expensive to maintain, performs better and supports advanced fea-
tures. New arrays can support larger capacities to accommodate the growth
of applications; have faster processing chips to deliver better performance; or
have new features such as snapshot copies. Finally, newer arrays are justied
to minimize the risk of hardware malfunction, as older arrays are perceived
as being less reliable.
Highlights
IT organizations justify new equip-
ment because it can accommodate
growth, process more quickly to
deliver better performance and
minimize the risk of hardware
malfunction.

Storage migrations made simple.
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Figure 1
Example annual migration requirements
Highlights
For most industries, estimates of
data growth can typically range
from 25 to 50 percent annually.
In many cases, technology refresh not only means replacing storage arrays,
but also upgrading associated servers to better meet service level agreements
or because the servers, like the arrays, have reached the end of their lease. In
addition, storage and server capacity are acquired annually or more often to
accommodate data and application growth. Estimates of data growth vary, but
they typically range from 25 to 50 percent annually for most industries.
So, every year, a typical organization acquires storage technology to replace
arrays on which lease or maintenance agreements are expiring, as well as addi-
tional capacity to accommodate anticipated growth. Thus, the IT organization
must move data between servers and storage for technology refresh on a very
regular basis. The storage mantra is: You have data, therefore you will move it.
Total on Floor (TB)
New (TB)
Replaced (TB)
Purchased (TB)
2005
300
70
115
45
2006
390
90
150
60
2007
507
117
194
77
2008
659
152
267
115
2002
136
31
45
14
2003
177
41
60
19
2004
230
53
77
24

Storage migrations made simple.
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IT organizations face many challenges associated with technology refresh—
particularly deciding how to deal with data growth and determining how,
when and where to move data. Some of the key issues associated with technol-
ogy refresh include:
• Leaseoverlapcostsorduplicatemaintenancecosts,whenoldandnew
equipmentareonthedatacenterooratthesametime
• Migrationofdatabetweenarraysfromdifferentvendors,astheremay
besignicantincompatibilities
• Riskofdatalossorcorruptionthatmayoccurifthemigrationisnot
doneproperly
• Prolongedapplicationdowntime,orevenaninabilitytorestartapplications.
This paper focuses on how organizations can meet these challenges by leveraging
data migration software.
Data migration software
Depending on the criticality of applications, the quantity of data to be moved
and allowable downtime, there are a variety of tools that organizations can use
to migrate data, each with its own considerations and limitations.
Offline migration methods
Ofine migration methods require that applications be taken ofine during
data movement, and therefore are suitable only when signicant downtime can
be tolerated. While the amount of downtime required typically depends on the
quantity of data being transferred, this ofine migration mechanism is not rec-
ommended for heavily used applications or those that must be accessible outside
of normal business hours. Ofine migration typically requires manual manipu-
lation of data or les, which can increase the risk of human error and may not
scale to distributed or remote scenarios.
Highlights
Organizations can meet these chal-
lenges by leveraging various types
of data migration software.
It is an ongoing challenge to decide
how to deal with data growth and to
determine how, when and where to
move data.

Restore from backup tapes
This method involves making a backup copy of data, then taking the associated
arrays and/or servers ofine to ensure that no new data is added. Then, the data
is restored from the backup tapes to the new arrays and/or servers. Once the
restore process is complete, the systems are brought online. While this is a low-
cost solution, especially as nearly all organizations already use backup software,
it requires signicant administrative attention and application downtime.
FTP transfer
This method involves manually copying les from the source systems to the target
systems via File Transfer Protocol (FTP). As it requires le-by-le movement, the
method is not recommended when the data contains large numbers of individual
les. FTP transfer does not provide control over the network bandwidth used for
migration, which can affect other applications and users in the network environ-
ment, nor does it enable verication of the complete transfer of data.
Online migration methods
Online migration methods generally allow data movement while applications
are up and running. Depending on the method chosen, however, these methods
can be limited to a single vendor environment. Other methods may consume
signicant central processing unity (CPU) overhead, potentially resulting in
application slowdown or other disruptions.
Array-based replication
While this method allows for high service level guarantees, it requires moving
between similar storage devices, increasing costs and limiting the data center
to a single vendor.
Storage migrations made simple.
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Highlights
Offline migration methods include
restore from backup tapes and
FTP transfer.
Online migration methods include
array-based replication, volume
management or replication, and
host-based mirroring.

Volume management or replication
Volume management is used primarily to control disk resources by mapping
the logical view of storage space with the actual physical disks. While it can
be used to move small amounts of data, it can be slow. This solution requires
a heterogeneous storage environment over an IP network and may require the
costly installation of additional software.
Host-based mirroring
Host-based mirroring or replication solutions generally focus on le-by-le
data movement to create a secondary data copy for disaster recovery purposes.
When used for data migration, this approach may put an additional burden on
application servers and may require high-cost management, especially in het-
erogeneous environments.
Online nondisruptive migration — Softek data migration products
There are a few products available in the marketplace today that were designed
to provide nondisruptive data migration—meaning that data movement occurs
without causing application outages or slowdowns. Softek’s data migration soft-
ware is the proven standard for online, heterogeneous data movement, meeting
the challenges of application availability and technical compatibility between
source and target storage. Softek’s TDMF software moves data while maintain-
ing application availability, making it easy to upgrade to new storage, improve
application performance and manage information availability through the
information lifecycle. So, whether the organization needs to upgrade to new
storage hardware (from any vendor to any vendor) or needs a more effective
way to migrate data based on cost/performance, TDMF software can provide
Storage migrations made simple.
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Highlights
Softek’s TDMF software makes it
easier to upgrade to new storage,
improve application performance
and manage information availability
through the information lifecycle.

the solution. Together with Softek Logical Data Migration Facility (LDMF™)
software for moving mainframe data at the dataset level, Softek TDMF tech-
nology provides the solution to meet a wide range of technology refresh and
other data migration needs.
An examination of real-world scenarios can demonstrate how Softek’s data
migration products are used to simplify technology refresh:
• Amanufacturingcompanyrunningamission-criticalOraclecustomer
orderandtrackingsystemonSolarisconductinglocalUNIX®array-to-
arraymigration.
• Alargebankrunningacreditanddebittransactionapplicationon
IBMz/OS®conductinglocalmainframearray-to-arraymigration.
• AmajorsavingsandloaninstitutionrunninganIBMDB2®,IBMCICS®and
VirtualStorageAccessMethod(VSAM)applicationwithhigh-availability
requirementsconductingmainframemigrationwithvolumeconsolidation.
• AFortune500nancialservicesrmrunningamission-criticalDB2
datawarehouseconductingmultiserverUNIXarray-to-arraymigration
withconsolidation.
• AFortune1000bankrunningaSybasenancialapplicationconducting
aglobalmigrationtonewstorageoverdistance.
• Aninsurancecompanywithamission-criticalclaimsprocessingapplication
onOracleconductingaglobalmigrationtonewserversandnewstorage.
• AFortune500bankrunningakeyenterprisecompliancemanagement
applicationconductingalocalMicrosoft®Windows®array-to-arraymigration.
The detailed descriptions of these scenarios that follow show how Softek
capabilities can meet technology refresh needs and streamline technology
refresh projects.
Storage migrations made simple.
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Softek’s software capabilities
can meet technology refresh
needs and streamline technology
refresh projects.
Highlights
A discussion of real-world imple-
mentations can illustrate how
Softek technology simplifies tech-
nology refresh.

Technology refresh examples
Local UNIX array-to-array migration
In this example, a manufacturing company running a mission-critical Oracle
customer order and tracking system on Solaris needed to move 3TB of legacy
data from an old storage array to a new storage array.
The challenges that the company faced were as follows:
• Limiteddowntime — Downtimewaslimitedtofourhoursontheweekend.
• Largevolumeofdata—Applicationstoragespannedten300GBvolumes.
• Increaseinvolumesize—Theplannedcapacitygrowthrequiredanincrease
involumesizeduringmigration.
The company considered the pros and cons of several different migration
options, including:
• Restorefrombackuptapes—Thisoptionwouldhaverequiredmorethan
fourhourstocopythedata,exceedingapplicationdowntimerestrictions.
• SunSolsticeVolumeManager—Thiswouldnotsupporttheincreasein
volumesize.
• Array-basedreplication—Thisoptionwouldhavebeenexpensivetoinstall,
andthecompanydidnotplantouseitfollowingthemigration.Inaddition,
rmwareupgradesrequiredonthelegacyarraystosupportthecurrent
array-basedreplicationversionwouldhaveaddeddowntimeandcomplex-
itytotheproject.
• VERITASVolumeReplicator(VVR) —Thisoptionwouldhaverequired
installingtheprerequisiteVERITASVolumeManager.
Storage migrations made simple.
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Highlights
In the first example, Softek software
helped a manufacturing company
move 3TB of legacy data from an
old storage array to a new one,
without significant downtime.