Integrating HP Data Protector software with
HP Data Deduplication Solutions
An analysis of how to implement data deduplication technologies
utilizing HP Data Protector software
Executive summary ............................................................................................................................... 2
Solution description .............................................................................................................................. 2
What is data deduplication? ................................................................................................................. 3
The benefits of data deduplication ......................................................................................................... 4
Details to know about object-level differencing ........................................................................................ 4
How much space does data deduplication really save? ............................................................................ 4
Example: 500 GB file server backup .................................................................................................. 4
Deduplication portfolio strategy from HP ................................................................................................. 6
Where does HP Data Protector software fit into the picture? ...................................................................... 7
HP Data Protector Advanced Backup to Disk Licensing ......................................................................... 7
Verify capacity for VTL ......................................................................................................................... 8
Licensing example ............................................................................................................................... 8
VTL configuration ............................................................................................................................. 8
For more information .......................................................................................................................... 10
Executive summary
This white paper provides complementary information on data deduplication technologies supported by the
latest Storage Solutions from HP. Data deduplication is a hot topic in data protection and therefore, also a
relevant topic for HP Data Protector software.
Solution description
HP Data Protector software is a backup and disaster recovery product that provides reliable data protection
and high availability for your expanding mission critical data. HP Data Protector network component
concept provides for tailor-made backup and recovery solutions ranging from a single system to thousands
of systems across multiple sites. HP Data Protector software fully supports HP data deduplication
technologies allowing you to recover files more quickly while reducing your data management and storage
costs. Data deduplication can increase your storage efficiency by a ratio of 50:1—that’s up to 5000%! The
extra capacity allows you to keep more backup data online and ready to restore at a moment’s notice.
Overall, the increase in storage efficiency brought about by deduplication lets you do more for less.
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What is data deduplication?
Data deduplication is the ability of an appliance or software to compare blocks of data being written to the
backup device with data blocks previously stored on the device. If duplicate data is found, a pointer is
established to the original data, rather than storing the duplicate data sets. This removes, or
“deduplicates,” the redundant data blocks. Data deduplication is done at the block or chunk level, not at
the file level.
This greatly reduces the volume of data stored.
Data deduplication is often used in conjunction with other forms of data reduction, such as conventional
data compression, to further reduce the data volume stored.
The best approach to data deduplication depends on your size and backup needs.
• Deduplication for enterprises: Object-level differencing, or accelerated deduplication, is a
good choice for enterprise customers because it focuses on performance and scalability. It delivers
the fastest restores, as well as the fastest possible backup by deduplicating data after it has been
written to disk. You can scale up to increase performance simply by adding extra nodes.
• Deduplication for midsize businesses and remote enterprise sites: Hash-based
chunking,
enterprises with remote sites because it focuses on compatibility and cost. It delivers a low-cost,
small footprint in a format-independent solution.
or dynamic deduplication, is a good choice for small and midsize businesses or large
A detailed description about deduplication techniques can be found in the “Understanding the HP
Data Deduplication Strategy” HP white paper at :
http://h71028.www7.hp.com/ERC/downloads/4AA1-9796ENW.pdf
Figure 1 shows the principal deduplication concept.
Figure 1: Deduplication Concept
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The benefits of data deduplication
There are a number of benefits realized by using data deduplication technology. The most compelling one
is the increase of effective capacity for storing backup data. This allows for longer retention periods for
backup data on disk, resulting in faster data recovery and higher service level agreements. HP disk-based
backup systems with built-in data deduplication also reduce space and power requirements for the
increased volume of protected data.
Read more about the deduplication benefits in the “HP Dynamic Deduplication—achieving a 50:1 ratio
HP white paper at: http://h71028.www7.hp.com/ERC/downloads/4AA2-0212ENW.pdf
”
Details to know about object-level differencing
Object-level differencing (accelerated deduplication) provides the best performance as the deduplication of
backup data is a post-backup process. That is the reason why the backup device (Virtual Tape Library) has to
be knowledgeable in terms of backup formats and data types to understand the meta data. HP Accelerated
deduplication will support HP Data Protector 6.0 software and specific data types at launch.
Initially by HP Accelerated deduplication supported data types are:
• File system backups
• RAW Disk
• Microsoft Exchange
More data types and future Data Protector software versions will be added to the support matrix over time.
The “HP StorageWorks Enterprise Backup Solution (EBS) Hardware/Software Compatibility Matrix” can be
found at: http://www.hp.com/go/ebs
.
How much space does data deduplication really save?
Two significant factors affecting the deduplication ratio for backups are:
• How long do you retain the data
• How much does data change between backups
Example: 500 GB file server backup
Retention Policy Data parameters
• 1 week, daily incrementals (5)
• 6 months, weekly fulls (25)
• Daily change rate = 1% (10% of data in
10% of files)
• No compression
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Figure 2: Disk Space requirements
Data stored normally
Data stored with
deduplication
1st daily full backup
1st daily incremental backup
2nd daily incremental backup
3rd daily incremental backup
4th daily incremental backup
5th daily incremental backup
2nd weekly full backup
3rd weekly full backup
500 GB 500 GB
50 GB 5 GB
50 GB 5 GB
50 GB 5 GB
50 GB 5 GB
50 GB 5 GB
500 GB 25 GB
500 GB 25 GB
25th weekly full backup 500 GB 25 GB
Total 12,750 GB
This example uses a system containing 500 GB of backup data that equates to 500 GB of storage for the
first traditional full backup. If 10% of the files change between backups, then a traditional incremental
backup would send about 10% of the size of the full backup or about 50 GB to the backup device.
However, because data deduplication operates at the block level, instead of the file level, in actuality only
a 1% change in the data has occurred. This means only 5 GB of block level changes or 5 GB of data
stored with deduplication. Over time, the savings multiply. When the next full backup is stored, it will not
be 500 GB. With deduplication the equivalent full backup is only 25 GB. A backup system with data
deduplication enabled would use the same amount of storage in six months that would typically be
required to store only one week of traditional backup data. Over a 6 month period data deduplication
would provide an 11:1 effective savings in storage capacity. It also provides the ability to restore from
further back in time without having to go to physical tape for the data. The key thing to remember here is
that the deduplication ratio depends primarily on two things:
1,125 GB
• What percentage of the data is changing between backups (percentage of data in percentage
of files)
• How long is the retention period of the backups stored on disk
For example, a 0.5% daily change in the data in 10% of the files would yield a 50:1 deduplication ratio
over one year of daily full backups. Obviously, the percentage daily change rate is quite difficult to predict
for complex systems, especially for applications like Exchange, SQL, and Oracle so benchmarking is
strongly advised.
As already indicated, backup data retention period and backup data change rate matters to find out what
the approximate deduplication ratio will be. Figure 3 shows the approximate space saving based on the
given daily change rate and backup policy.
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Figure 3: Deduplication Ratio
Backup policy
50:1
32:1
18:1
25:1
19:1
13:1
6 months
31:1
23:1
15:1
1 year
46:1
29:1
17:1
Daily change rate
0.50% 31:1
1.00% 24:1
2.00% 16:1
Daily full and weekly full Daily incremental and weekly full
4 months* 6 months 1 year 4 months*
37:1
27:1
17:1
* 4 months = 5 daily + 17 weekly backups Ratio = data sent vs. data stored
Deduplication portfolio strategy from HP
HP has selected two deduplication technologies—one for enterprises and one for the SME and remote offices.
• Accelerated deduplication, available for HP StorageWorks Virtual Library Systems.
Used on HP VLS6000/9000/12000
• Dynamic deduplication, built into HP StorageWorks D2D Backup Systems.
Used on HP D2D2500 and D2D4000
Figure 4 depicts the latest announced Entry-to-Enterprise level storage devices and their
deduplication capabilities.
The HP StorageWorks D2D2500 and D2D4000 Backup Systems implement HP Dynamic deduplication
technology. These range in size from 2.25 TB to 7.5 TB and are aimed at remote offices or small enterprise
customers. The D2D2500 has an iSCSI interface to reduce the cost of implementation at remote offices,
while the D2D4000 offers a choice of iSCSI or 4 Gb FC.
The HP StorageWorks Virtual Library Systems implement HP Accelerated deduplication technology and are
all 4 Gb SAN-attach devices that range in native user capacity from 4.4 TB to over a petabyte with the
VLS9000 and VLS12000 EVA gateway. Hardware compression is available on the VLS6000, 9000, and
12000 models, achieving even higher capacities. The VLS9000 and VLS12000 use a multi-node
architecture that allows the performance to scale in a linear fashion. With eight nodes, these devices can
sustain a throughput of up to 4800 MB/sec at 2:1 data compression, providing the SAN hosts can supply
data at this rate. HP Virtual Library Systems will deploy the HP Accelerated deduplication technology.
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Figure 4: HP StorageWorks Disk-based Backup
Where does HP Data Protector software fit into the picture?
Deduplication, today, is a feature provided by HP StorageWorks Virtual Library Systems and
HP StorageWorks D2D Backup Systems and other vendors’ hardware.
Deduplication on the in the previously mentioned paragraph storage devices happens either as “Inline
deduplication” (Dynamic deduplication) or as “Post-Process” (Accelerated deduplication) technique.
Both ways are completely transparent to HP Data Protector software.
HP Data Protector Advanced Backup to Disk Licensing
As of 1st July, 2008, the HP Data Protector Advanced Backup to Disk license will cover the
planned/consumed capacity on HP Data Protector file libraries and virtual tape libraries (VTL).
In cases where HP Data Protector software is using the VTL exclusively, it is recommended to license a
quantity of Advanced Backup to Disk licenses matching the physical capacity of the VTL. HP calls the
physical VTL capacity “usable native capacity.” Other vendors call it “raw capacity.” The new physical
size/consumption licensing model does not require compression rates and deduplication ratios to be
considered. RAID overhead does not to be considered as well.
The relevant HP Data Protector Advanced Backup to Disk licenses are:
• B7038AA capacity license for 1 TB of backup disk storage
• B7038BA capacity license for 10 TB of backup disk storage
• B7038CA capacity license for 100 TB of backup disk storage
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Note:
Accelerated deduplication capacity licenses are available for current VLS
models (VLS62xx, VLS66xx, VLS9000, VLS12000). These licenses are not
part of the HP Data Protector licensing schema.
Verify capacity for VTL
The recommended tool to verify consumed or allocated disk space on virtual tape libraries is the web-based
Command View VLS management interface.
Figure 5 depicts the relevant view within the Command View VLS management interface to evaluate the
amount of allocated and consumed disk space on the VTL.
Figure 5: VLS Management Interface
Licensing example
VTL configuration
In the example depicted in Figure 6, the virtual tape library (VTL) holds 5 TB of protected backup data
managed by HP Data protector software.
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Figure 6: VLS Licensing Example
Usable native capacity of a virtual tape library (VTL) is the size on disk of the virtual tape library consumed
by all protected HP Data Protector backups as reported by the VTL.
A total of five B7038AA Advanced Backup to Disk licenses are required to allow HP Data Protector
software to utilize all 5TB in the example depicted in Figure 6.
Note
Virtual Tape Libraries can be upgraded using capacity-kits to extend the
VTL’s usable native capacity. Further backups to the virtual tape library
(VTL) in the example in Figure 6 will exceed the total licensed Advanced
Backup to Disk capacity therefore additional licenses will be required.
Proper capacity planning is mandatory to not exceed the total licensed
capacity.
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For more information
g
HP StorageWorks D2D Backup Systems (D2D): (http://www.hp.com/go/d2d).
HP StorageWorks Virtual Library Systems
(VLS): (http://www.hp.com/go/vls).
Data Protection Solutions with Deduplication
: (http://www.hp.com/go/deduplication)
Technology for better business outcomes
© 2008 Hewlett-Packard Development Company, L.P. The information contained herein is
subject to change without notice. The only warranties for HP products and services are set
forth in the express warranty statements accompanying such products and services.
Nothin
herein should be construed as constituting an additional warranty. HP shall not be
liable for technical or editorial errors or omissions contained herein.
Itanium is a trademark or registered trademark of Intel Corporation or its subsidiaries in
the United States and other countries.
4AA2-2654ENW, September 2008
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