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Dell
PowerVault
DL2000
Backup
Performance
A Dell Technical White Paper
Dell PowerVault DL2000 Powered By
Symantec
Muffadal Quettawala and
Scott Reichmanis
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Introduction
The Dell PowerVault ™ DL2000 – Powered by Symantec Backup Exec
is a exible, cost-effective backup solution for simple, manageable
data protection.
This whitepaper evaluates the throughput performance capabilities
of the PowerVault DL2000 in its two hardware congurations – Value
Series and Performance Optimized1. With this information, the
end-user will be able to accurately size their backup infrastructure
to meet backup window requirements by scaling the number of
DL2000s needed for their environment and by optimizing backup
schedules and balancing backup workloads.
The PowerVault DL2000 Performance Optimized version was
evaluated in a six (6) Gigabit Ethernet (GbE) port conguration and
the DL2000 Value Series version was evaluated in both a six (6) GbE
port and a two (2) GbE port conguration. The backup client system
infrastructure consisted of a Microsoft® Exchange Server 2007
environment and a Microsoft® SQL Server® 2008 environment as
illustrated in Figure 1 below.
Figure 1 - Backup Infrastructure Environment
1
The DL2000 – Powered by Symantec also comes in four (4) different software editions but they have no
impact on backup throughput, and hence are not compared in this whitepaper.
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The maximum backup throughput achieved for each of the three
system congurations is summarized in the table below:
Conguration End-to-end Effective
Backup Throughput for
Microsoft Exchange 2007
(GB/hr)
PowerVault DL2000
Performance
Optimized with six (6)
GbE ports
PowerVault DL2000
Value Series with six
(6) GbE ports
PowerVault DL2000
Value Series with two
(2) GbE ports
1833 2645
1578 2218
991 1403
End-to-end Effective
Backup Throughput
for Microsoft SQL
2008 (GB/hr)
These results provide an end-user with valuable data and insight for
planning, sizing and using the DL2000 Backup to Disk Appliance
within their IT infrastructure.
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Test Setup
The test setup details are summarized in the table below:
Backup
Solution
DL2000 – Powered
by Symantec
Backup Exec with
Performance
Optimized hardware
and 6 GbE ports
DL2000 – Powered
by Symantec Backup
Exec with Value
Series hardware and
6 GbE ports
DL2000 – Powered
by Symantec Backup
Exec with Value
Series hardware and
2 GbE ports
1
1
1
No. of
MD1000
Enclosures
1
2
5
1
2
5
1
2
2
Standard
Standard
Standard
Backup Type Clients
6, 12 and
24 Microsoft
Exchange
Software
Compression
Software
Compression
Software
Compression
Software
Encryption
Software
Encryption
Software
Encryption
2007 clients
with average
Information
Store size of
approximately
36 GB
6, 12 and 24
Microsoft SQL
2008 clients
with average
database
size of
approximately
36 GB
Note: The 6, 12
and 24 clients
were used
for 1, 2, and
5 enclosure
benchmarks
respectively.
3,4,5
5
1
The DL2000 NIC ports were set up in a Smart Load Balanced (SLB) team using the Broadcom Advanced Control Suite
(BACS) with receive and transmit buffer sizes set to 1024. TCP Ofoad capabilities are not available to a team with
heterogeneous network adapters. To enable TOE, congure the DL2000 with each GbE port assigned to a separate
subnet. The Dell PowerConnect 6248 10/100/1000BASE-T Ethernet switch was used to connect the DL2000 with the
client systems in a dedicated network environment.
2
Each MD1000 enclosure contained 15 1TB 7.2K SATA disk drives and disk groups were automatically congured via
the Symantec Backup Exec Storage Provisioning Option (SPO).
3
The clients ran on Windows Server 2008 64-bit Standard Edition. Synthetic database load for the backup system
clients was generated using the Microsoft Exchange Load Generation tool, version 08.02.0045.000 for Exchange
clients and the RedGate SQL Data Generator version 1.2 for SQL clients.
4
The size of the total backup set was sufcient to eliminate in-memory caching effects and maintain sustained
performance through a 10 minute measurement interval
5
Backups were performed in a homogenous application server environment, i.e. the environment consisted of only
Exchange Servers or only SQL Servers). The Exchange Information Stores and SQL databases were backed up in a static
environment, i.e. no transactional database activity was taking place during backup operations.
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For the DL2000 - Powered by Symantec Backup Exec, the following
additional conguration settings were used when performing
backups:
• Each backup client system was congured as a separate backup
job
• The maximum number of concurrent jobs per virtual disk was set
to one (1).
• Consistency checks and backup verication were disabled on all
backup jobs to minimize pre- and post-processing backup times.
• For Software Encryption backups, 128-bit AES keys were used.
• For Software Compression backups, Backup Exec’s software
compression feature was used. Note: For SQL 2008, the SQL
Server 2008 Enterprise Edition software compression feature
was disabled.
The next section provides a detailed summary of the throughput
results obtained for Microsoft Exchange 2007 and Microsoft SQL
2008 clients respectively.
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Results and Analysis
The gures below compare the end-to-end backup throughput results
obtained for PowerVault DL2000 - Powered by Symantec Backup
Exec with Microsoft Exchange and Microsoft SQL clients. The results
compare systems with one (1), two (2) and ve (5) enclosures for
three (3) different backup types - Standard, Software Compression
and Software Encryption.
Microsoft Exchange 2007 Microsoft SQL 2008
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The maximum backup throughput achieved for each of the three
system congurations is summarized as follows:
Backup
Solution
DL2000
Performance
Optimized with 6
GbE ports
DL2000 Value
Series with 6
GbE ports
DL2000 Value
Series with 2
GbE ports
1
Adding clients beyond 12 reduced throughput due to processor limitations on the DL2000 Value Series.
2
For DL2000 Value Series with two (2) GbE ports, throughput was limited by the two (2) GbE ports. Increasing
the number of MD1000 enclosures and backup client systems had little to no effect on the backup throughput.
3
Throughput was measured at each of the NIC ports of the DL2000 during a 10 minute interval of ingest.
Values were adjusted by 4.3% to account for the Ethernet frame preamble, Ethernet header and TCP/IP
Packet header overhead. Compression ratios were factored, where applicable in the aggregate throughput
measurements to arrive at end-to-end effective throughput. Software compression ratios were 1.2 for
Exchange and 1.7 for SQL.
2
Number of
Backup client
systems
24 5 1833 2645
1
12
12 2 991 1403
Number of
MD1000
Enclosures
2 1577 2218
Exchange
Throughput3
GB/hr
SQL
Throughput3
GB/hr
As seen in the table above, backup throughput rates for the DL2000
Performance Optimized version with six (6) GbE ports were found to
be up to 17% faster than DL2000 Value Series with six (6) GbE ports
and up to 47% faster than DL2000 Value Series with two (2) GbE
ports.
The following discussion analyzes the data gathered during the
benchmark from three different perspectives.
Analysis by the Number of MD1000 Enclosures:
In general, going from one to two enclosures provided a signicant
increase in throughput. Beyond two enclosures the benets were
minimal. With the Value Series hardware, going beyond two (2)
MD1000 enclosures resulted in a small decrease in throughput in a
few cases since the processor became the limiting factor.
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Analysis by number of GbE ports:
For the six (6) GbE port systems the backup throughput was never
network limited. For the PowerVault DL2000 Value Series hardware
with only two (2) GbE ports, backup throughput rates were network
limited in all cases where there were two (2) or more enclosures. For
the one (1) enclosure case, there were not enough clients to saturate
the NIC bandwidth
Analysis by Backup Type:
Software compression and software encryption are performed
by the backup clients and thus do not impact performance of the
PowerVault DL2000 – Powered by Symantec media server. Software
compression can however increase end-to-end effective backup
throughput by reducing the size of the backup data before it is
transferred from the backup clients, as demonstrated in the results
above.
Note however that software compression and software encryption
consume processor resources on the backup clients and can
negatively impact end-to-end backup throughput if the clients do not
have sufcient processing power.
Conclusion
The Dell PowerVault ™ DL2000 – Powered by Symantec Backup Exec
provides a high performance, integrated backup-to-disk solution that
ts into any data infrastructure environment.
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Further Reading
Additional information about the Dell PowerVault ™ DL2000 –
Powered by Symantec Backup Exec can be found at
http://support.dell.com
www.dell.com/prosupport/mobility
www.dell.com/getprotectedandconnected
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