A successful data migration process can be used for a one-time migration, or as a standard procedure for future migrations employing a consistent, reliable and repeatable methodology incorporating planning, tool implementation and validation. Dell data migration services can help. This whitepaper explores the Dell storage portfolio, Dell methodologies for migration and the use cases for migrating customers over to Dell Storage.
1. Methodologies for Data Migration
to Dell Fluid Data Architecture
A Dell Technical White Paper
Executive summary
The dictionary entry for “challenging” could very well The impact of explosive data growth is felt at every level
describe enterprise storage migrations. Complex and often of the enterprise. Typically, data migrations and storage
problematic, data migrations challenge even the most provisioning are manual processes that consume IT resources
seasoned IT administrators with narrow downtime windows, while disrupting users and applications. Backups take
risk of data loss, business-critical application availability, 24/7 increasing amounts of time to complete, and they are more
user access requirements, and other factors. IT departments costly to maintain. Utilization rates vary dramatically, as some
may not have the needed skill set or may not want to spend storage arrays or file servers run out of capacity while unused
valuable resources migrating data. In addition, data centers capacity languishes on others. Users and applications are
may support multiple operating systems like Microsoft® statically mapped to physical devices, creating configuration
Windows®, UNIX® and Linux® technology, while the storage challenges whenever changes occur in the environment.
ecosystem may also include hardware from more than one And many traditional storage infrastructures (from mergers
vendor. Inflexibility of traditional storage infrastructures can and acquisitions) have evolved haphazardly without a solid
complicate matters even further. strategy for consolidating.
3. Dell data migration best practices: Dell has evolved from a storage
reseller to a storage innovator. We did it by starting fresh, building
the right storage architecture without the burden of legacy
intellectual property (IP), and designing solutions based on what
customers truly wanted.
It wasn’t just about data growth; Storage portfolio
customers need to know how they Enterprise data volumes continue to
could respond to growth and constant grow exponentially while IT budgets
change. They wanted to shift their focus continue to shrink. Dell helps customers
from keeping the lights on to future tackle these challenges by standardizing
strategy — from operation to innovation. IT infrastructures, simplifying operations
With this in mind, Dell services put and automating processes. Efficiencies
together a comprehensive data gained through virtualization,
migration strategy to help customers automation and consolidation will help
migrate from their legacy storage to the your business prepare for future growth
Dell Fluid Data™ architecture. while saving time and resources.
Dell Services has a stable, proven Dell can help you:
process for performing data migrations • Optimize the computer, processor,
backed by a wide range of capabilities networking and storage resources
and technologies. This means we can already in your IT infrastructure
adapt to any customer environment • Increase overall utilization by
while maintaining the integrity of best- eliminating isolated or stranded
practice implementation. Whether resources
you’re moving accessible data off- • Reduce total cost of ownership (TCO)
hours, business-critical data during a through standard-based solutions,
tight maintenance window, or need simplified operations, virtualized
minimal disruption for a mission-critical storage and seamless scalability
environment, Dell Services has the right • Improve IT performance
solution for the right value. Backed by
the experience of thousands of global Dell’s Fluid Data™ architecture,
customer engagements, Dell Services for comprised of Dell™ Compellent™, Dell
planning, migrating and validating data EqualLogic™ and Dell PowerVault™
migrations can help you simplify your storage solutions — as well as other
move to the storage platform that’s right Dell storage tools and utilities — can
for your business. help organizations of any size realize
the full value of their IT investments. It
This whitepaper describes Dell’s can also protect vital enterprise data,
expertise in data migration across a ensuring high business continuity while
range of technologies and use cases. maintaining flexibility and scalability.
3
4. Dell Compellent PowerVault SANs PowerVault™ NX3500
Dell PowerVault iSCSI and Fibre Channel
arrays are the ideal SAN solution for
Utilizes Dell™ Fluid File System and the
entry-level storage consolidation
PowerVault SAN back end for Internet
requiring high availability, high
SCSI (iSCSI), CIFS and NFS access to
performance and business continuity
block and file data — enabling a single
without sacrificing ease of use and
file share to scale up to the capacity
reliability. Designed for flexibility, the
of the SAN array deployment. With
newest PowerVault SANs support
PowerVault™ NX3500, you can help
a range of drive types, enclosures
prevent the data silos and server sprawl
and RAID levels — all within a single
caused by an increasing amount of
Dell Compellent Storage Center delivers array. With high-speed iSCSI and Fibre
data (email, video, MP3 user home
an all-in-one storage solution that Channel interfaces, PowerVault arrays
directories). Start small and still enjoy
always puts data in the right place at provide multigenerational/multiprotocol
the value of high performance, unified
the right time for the right cost — and single management interface and
storage. And as your storage needs
dynamically adapts to meet changing support.
grow, you can dynamically add or
business needs.
modify block and file capacity without
Network Attached Storage (NAS)
disrupting existing applications and
Dell Compellent storage controllers are
storage systems.
also designed to deliver high availability.
Redundant and hot-swappable power
supplies and cooling fans help ensure
nonstop operation when problems
arise. These controllers also offer the Grow block and file capacity non-
flexibility to meet changing enterprise disruptively with the EqualLogic™
requirements. Customers can select FS7500, the only scale-out unified
either one or two controllers per SAN, storage architecture optimized for
and then use Fibre Channel, FCoE midsize and smaller deployments. The
and/or iSCSI connections to servers, Dell EqualLogic FS7500 adds network-
including the latest iSCSI and FCoE attached storage (NAS) capability to the
interconnects. The controllers connect EqualLogic product line to provide a
to any open-system servers without the high performance, scalable and unified
need for dedicated agents. storage solution. The FS7500 is powered
by the Dell Fluid File System (Dell Fluid
EqualLogic FS), Dell’s high-performance, clustered,
and network-accessible file system. Dual
active-active controllers, redundant
power supplies and fans, and battery-
backed cache make the FS7500 an ideal
Dell EqualLogic™ arrays are virtualized solution for NAS deployments requiring
iSCSI SANs that combine intelligence high availability and reliability.
and automation with fault tolerance to
provide simplified administration, rapid
deployment, enterprise performance,
reliability and scalability. EqualLogic is
an excellent choice for performance
and capacity-intensive applications.
The virtualized, modular EqualLogic
architecture allows IT managers to
purchase only the storage they need,
when they need it.
4
5. If you’re thinking about new storage solutions and complexities around data migration,
consider the following key factors and how Dell Data Migration consultants can help:
Key migration factors
Key factors Description Dell capabilities
Performance Balances network bandwidth A diverse toolset where
and system overhead with migration can be throttled
migration performance accordingly to strike a
metrics balance of migration speed
and application/network
performance
Heterogeneous Deploys the right migration A holistic vendor-agnostic
hardware and OS tools that minimize multi- migration solution that spans
vendor restrictions in complex multiple OS and supports
environments numerous storage platforms
Application Identifies and manages A choice of offline or online
downtime varying degrees of application migration depending on the
criticality and acceptable customer requirements
levels of downtime
Scalability Factors local and global data Appliance- or software-based
growth into terabyte and solutions that can be used for
petabyte migrations routine migrations in the data
center
Data migration methodology
A successful data migration process can be used for a one-time migration, or as
a standard procedure for future migrations employing a consistent, reliable and
repeatable methodology incorporating planning, tool implementation and validation.
The chart below shows a typical data migration workflow that can be used as a
reference.
Dell data migration game plan
Pre-production
Planning Migration Validation Cutover
Testing
Ÿ Define migration Ÿ Setup testing Ÿ Setup final Ÿ Collect Ÿ Move
goal migration migration migration application to
Ÿ Define migration environment environment statistics the target
requirement Ÿ Validate HW/SW Ÿ Install migration Ÿ Verify the storage
Ÿ Understand and migration software completion of environmen
business impact tools Ÿ Perform the migration based on
Ÿ Data Collection Ÿ Perform migration based Ÿ Validate cutover plan
Ÿ Define HW/SW migration testing on plan application Ÿ Create final
and tools based on plan functionality report
Ÿ Create migration Ÿ Collect and Ÿ Create migration Ÿ Run the new
plan validate data report environment
Ÿ Update final during the
migration plan defined time
frame
Ÿ Retire the
previous
environment
5
6. Planning • Hardware vs. Software: Some
Planning is critical for a successful migration tools require plugging the
data migration. Dell Migration Services appliance into the environment, while
considers the following factors when others are based on OS filter drivers.
evaluating a data migration project: We offer a wide range of choices for
migration use cases
Business impact • License: Cost of the license to be
The impact should be clearly explained considered
to stakeholders so they have the
appropriate expectations. Below are Migration project plan
some factors to be considered in this Once the aforementioned factors are
process: defined and agreed upon, the Dell
• Online or offline methodology planning team documents all the
• Applications impacted discoveries and planning steps in the
• Workload distribution between master migration project plan. This plan
customer and Dell evolves as the project progresses.
• Backup of data to be migrated in place
• Required staging of storage / Proof of concept (POC)
hardware POC is a significant first step in the
overall execution process as it helps
Data collection set up the baseline for the migration
Understanding the existing environment project. It establishes an initial test plan
is key to successful planning. The to validate the co-operative migration
following information should be plan between the customer and Dell
collected: Migration Services. Once the POC is
• Server information (OS version, successfully completed, Dell Migration
applications, firmware, drivers, etc.) Services and the customer agree on
• Storage environment (topology, data the viability of the validation and the
size, performance, etc.) execution of the migration project plan
• Data classification & tiering of apps to begins.
define priority
• Existing issues Validation
• Users and business segments involved Once data is fully migrated to the
target, migration validation takes place.
Migration tools identification Validation is one of the most important
Dell Migration Services uses multiple post-migration tasks and includes the
tools during the process. To select the following areas:
Note:
right tools, we consider the following • Data completeness: All data defined
For a fee, Dell Migration Services also
factors: for migration on the source are
provides consulting services to assess
the customer migration environment. • Performance: This refers to the speed migrated to the target environment
of the migration — a combination • Data integrity: The data itself, as well
of the tool’s software architecture, all data attributes, dependencies,
migration bandwidth, source/target security, etc. are successfully migrated
capabilities, application performance, • Data functionality: migrated data is
etc. mapped to the right application and
• Online or offline: Depending on functions correctly and as expected
customer requirements, we choose
tools that offer migration while the Cutover (Deployment)
LUNs are either online or offline Typically, legacy environments remain
• Roll-back capability: Software that running until extensive validation is
may provide the capability to roll back performed on the new storage. Once
data in case the migration runs into validation is complete, customer is
any issues cutover to the new storage.
6
7. Data Migration Expertise: Dell experts have migrated petabytes
of data worldwide ranging from SAN, NAS and file systems
marketed by a variety of vendors. Our Data Migration Services
practice takes the burden of migration responsibilities off your
shoulders and puts it in the capable hands of expert storage
migration consultants.
We have the experience and proven vary depending on the environment,
methodologies to deal with any migration performance is roughly
complexities your particular migration 500GB/hr. Currently, Thin Import only
may present. works over fibre channel, which means
the source array and destination CML
Dell consultants can help with: array must have fibre channel FE ports.
The current or planned host connectivity
Block level
method can be different, but the import
process can only be performed over
FC array-based migration
fibre channel.
Thin Import is a built-in feature of
Storage Center on Compellent arrays.
Host-based migration
Data from external storage arrays, which
Array-based migration solutions do not
are typically thick-provisioned, can be
solve all data migration scenarios. In
migrated to thin-provisioned volumes
some cases, host-based tools, which
on the Compellent drive. No additional
are OS specific, are an effective way to
licenses are required.
migrate data. Dell Migration Services
The Thin Import process works at
have verified and tested the following
a block-level, using synchronous
tools for multiple OS environments.
replication to import the data. All
Each host-based tool has stipulations
blocks are read on the source LUN
and limitations around migrating data.
and then written to the destination
Dell Migration consultants will discuss
volume on the Compellent with blocks
the details of each solution with your
consisting of all zeroes being omitted.
team during the planning phase.
The result is a thin-provisioned volume
on the Compellent. Although it can Note:
For security reasons, Thin Import is
primarily an offline activity.
Zoning for Thin Import
Fabric A Fabric B
CLARiiON SPA0, CML Controller 1 Port 1 CLARiiON SPB0, CML Controller 1 Port 2
CLARiiON SPB1, CML Controller 1 Port 1 CLARiiON SPA1, CML Controller 1 Port 2
CLARiiON SPA0, CML Controller 2 Port 1 CLARiiON SPB0, CML Controller 2 Port 2
CLARiiON SPB1, CML Controller 2 Port 1 CLARiiON SPA1, CML Controller 2 Port 2
Important
1. This is an example only - actual ports on source and destination arrays may vary
2. Do NOT just configure and enable these zones - follow step-by-step instructions or data loss may occur.
Fig 1: Sample FC connectivity of Dell CML array with a third-party array
7
8. VMware or virtual. The image of the source
Migrating from legacy storage vendors contains the server’s system state (the
has never been easier for customers server’s configured operating system
running VMware Enterprise and and applications) and all of the source
Enterprise Plus editions with the built- server’s data.
in tool called Storage vMotion. Storage
vMotion eliminates the need for service The Double-Take ‘Move’ function
disruptions with live, automated uses data replication to allow users to
migration of virtual machine disk files continue accessing and changing data
from legacy storage to a new Dell during the migration. As changes are
destination. Non-disruptive migration made on the source, replication updates
of virtual machine disk files to different the image of the source stored on the
classes of storage enables cost-effective target in real time. Double-Take Move
management of virtual machine disks does not replicate the entire file, only
based on usage and priority policies as the file changes. When you’re ready
part of a strategy for tiered storage. to cutover to the new server/storage,
Double-Take Move then applies the
source system state and after a reboot,
Virtual Machines
makes the source available on what was
App App App the target server hardware.
OS OS OS
Migrating data to a new storage array
often provides a good opportunity to
migrate or upgrade to the latest Dell
ESX Server
PowerEdge™ server platforms as well
(see Figure 3). Double-Take software
includes tools such as Full-Server
Failover (FFO) for server migrations
that remove Windows hardware driver
dependencies, enabling administrators
to migrate entire systems — including
the system identifier (SID), registry,
system files and applications — through
a GUI while those systems are still
Storage VMotion running (see Figure 3). Once the
synchronization is complete, you
can shift the new server and storage
Fig. 2: Sample Storage vMotion platforms into production.
connectivity of Dell storage array
with a third-party array
Windows
Server
Delivered on the Windows platform, Dell Migration
Migration Services uses Double-Take as Dell PowerEdge 2650 Dell PowerEdge R900
with Microsoft Exchange with Microsoft
the solution of choice for a majority of and Double-Take software Exchange and
customers. Double-Take software
Double-Take is a comprehensive Data
workload migration solution that allows Migration
TM
Production Dell EqualLogic
an entire server, known as a source, to Dell/EMC Cx300 PS Series
be moved by mirroring an image of Fibre Channel SAN iSCSI SAN
that source to the target. The source Fig. 3: Sample Double-Take use cases:
and target servers can be physical Server or array migration
8
9. LVM Symantec volume manager
LVM is disk management functionality One of the most widely used volume
built into many UNIX/Linux platforms. managers in the industry today is
Each OS has its own nuance around VxVM from Symantec, which is part
provisioning disks within LVM but one of the Storage Foundation Suite.
common denominator among them is Symantec Volume Manager (VxVM)
that it provides an abstraction level layer is an online storage management
between the OS and disks — whether tool that provides a logical volume
it’s local, on a DAS, or SAN. From a data management layer, which overcomes
migration standpoint, a typical LVM the physical restrictions of hardware disk
process involves setting up a mirror of devices by spanning volumes across
the data on the legacy storage volumes multiple spindles. Through the support
to the new volumes. The next step is to of RAID redundancy techniques (in
synchronize the new volumes. Once data migration’s case RAID 1), VxVM
the sync is complete, the mirror can be enables migration of volumes across
broken at cutover. This usually involves heterogeneous storage arrays.
detaching the source volumes. Some Mirroring can be set up with the aid of
volume management software includes the VxVM GUI called VMSA or through
commands to automate this process. command line. Dell Migration Services
With close to no downtime, mirroring is strongly recommends using command
a great way to migrate data over to Dell line for mirror-based migration since it
storage. offers more control over what is being
executed behind the scenes. A known
Veritas Volume Manager
limitation of Symantec Volume Manager
Solaris AIX Linux HP-UX is that RAID 5 volumes are inferior
candidates for VxVM-based migrations
and other tools must be explored to
accomplish the task.
Solaris
Solaris Volume Manager provides
mirror functionality across arrays. To
administer Solaris Volume management,
use the GUI (called Solaris Management
Console) or the command line.
AIX
Note:
Source Array: Target Array: AIX LVM is built into the OS and
For simplicity and standardization, LUN
Dell|EMC Compellent leveraged for cross-platform storage is considered an array level object,
Fig. 4: LVM-based array migrations are migrations as long as the source disks while volume is an LVM term.
OS specific are under the control of the LVM. Multiple LUNs can constitute a volume.
9
10. HP-UX appliance provides multi-protocol
Mirror/UX, a licensed product from (iSCSI, FC) block level and synchronous
HP, provides the functionality to mirror mirroring across heterogeneous
volumes and can be extremely useful storage. It also supports a diverse mix
for data migrations with a stipulation of operating systems, which makes
that the source volumes are not striped migration seamless and pain free for
within the logical volume. The output the customers since no downtime
below illustrates a scenario that would is required for the duration of the
not allow for LVM-based migration. migration.
hp5:/home/noman# lvdisplay -v /dev/ There are two downtime windows
vg5/mirror_1 | more required, however: one upon insertion
--- Logical volumes --- of the appliance, and the second upon
LV Name /dev/vg5/mirror_1 cutover to the Dell storage.
VG Name /dev/vg5
LV Permission read/write
LV Status available/syncd
Mirror copies 0
Consistency Recovery MWC
Schedule striped
LV Size (Mbytes) 1008
Current LE 252
Allocated PE 252
Stripes 3
Stripe Size (Kbytes) 128 Original
IO path
Source
Array
Bad block on Change IO
path to NSS
Allocation strict Activate
Mirror
IO Timeout (Seconds) default
FalconStar NSS
Additionally, the source and target disks
must be part of the same volume group 1. Prepare Zoning for indirect access
Target 2. Move IO path: Downtime (Reboot)
to proceed with a data migration. Array 3. Activate Mirror while online
4. Change Mirrorrole while online
5. Remove mirror while online
Linux
Fig. 5: A simplified NSS Gateway
Linux LVM is built into the OS and
solution from FalconStor
leveraged for cross-platform storage Software would entail this setup
migrations as long as the source disks
are under the control of the LVM. If
LVM is not implemented, Double-Take Backup and recovery
is another choice for supported file One of the most traditional methods of
systems. performing data migration is backing
up the data to disk or tape, setting
Appliance-based migration up new storage and restoring to the
Dell Migration Services has partnered new storage. This is also the most
with FalconStor Software where time consuming way to migrate data
previously mentioned tools and because of the downtime required for
use cases may not fit the customer the duration of the backup, and then
high performance data migration another downtime needed for restore.
requirements. Using NSS Gateway This is usually considered a method of
Appliance Software, which runs on a last resort for migrating data.
two-node Dell R710 cluster server, Dell
can migrate any existing third-party
SAN storage over to Dell storage with
minimal downtime. The HA FalconStor
10
11. File level CIFS
Dell Migration Services has partnered
NAS with Quest Software for CIFS/Windows-
NAS, or file data migration, involves based data migrations. The Quest
creating a copy of the data and moving Secure Copy technology enables Dell
it from one array/file server to another Services to offer fast, proven enterprise-
with little disruption to the production class data migration. This host-based
environment. The optimal data data migration software eases the
migration tools for NAS not only migrate pain often associated with typical NAS
the data and the directory structure but migrations. The first sync between
also the file attributes and the ACLs over source and target can be online, and
to the target storage. Typical migration the I/O operation can continue to the
use cases around NAS include: source array. For a final sync, however,
• Consolidating multiple Windows the I/O operation must to be ceased.
servers onto a common platform to
reduce server sprawl NOTE: This final sync can take up to 20%
• Consolidating multiple UNIX-based of the first sync time and requires total
exports (from multiple UNIX hosts) downtime on the source array shares
onto a common platform being migrated. If an array has a NAS
• Creating a cross-platform file appliance attached and additional hosts,
sharing (Windows and UNIX servers) those additional hosts do not need to
environment that scales beyond come down to migrate shares on the
the limit of traditional File Shares NAS appliance.
(Windows) and UNIX-based exports
rsync
Dell Migration Services offers tools for Long established in the UNIX world,
CIFS- and NFS-based migrations. rsync is an open source OS- and
storage-agnostic tool that remains a top
choice among storage administrators.
NAS: NFS amd CIFS Dell uses this powerful OS built-in utility
Windows Systems UNIX Systems for all NFS-based migrations.
Ethernet CIFS NFS
Fig. 6: A typical NAS migration involves
CIFS & NFS
11