Hampshire Police Authority
Item: 8
IT and Information Systems Strategy Committee
7 February 2008
Data Storage
Report of the Chief Constable
Contact:
Steve Vercella, Head of IT
0845 045 45 45 ext 1406
Email: [email protected]
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Summary
1.1
This report provides the IT and Information Systems Strategy
Committee with information concerning the issues facing the IT &
Communications (IT&CS) Department in managing large and
increasing volumes of data and plans in place to improve this
management.
1.2
The ever increasing requirements for storage of electronic data on
computer systems means that IT&CS have had to review how this is
managed in order to improve its efficiency and contain costs.
1.3
The data storage issues identified are:
1.4
1.3

The increasing volumes of data to be stored.

The currently inefficient way storage capacity is managed.

Management issues with the current storage architecture.

Environmental issues linked with the increased requirements for
storage systems.
Work on an improved approach to data storage is underway at three
levels:

Implementation of improved data compression and expansion of
storage capacity for RMS.

Development of a storage strategy covering “virtualisation” of
existing storage systems to improve the efficiency of use of existing
storage capacity.

Identification of the requirement for an data archive strategy.
This report recommends that:

The work underway be noted.
www.hantspa.org
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Background
2.1
Traditionally Hampshire Constabulary has implemented applications by
purchasing individual computer servers to support and run an
application. The server included data storage disks (dedicated to that
server) sized for the initial storage requirements of the application with
some capacity for future growth. As the storage requirements for the
application increased beyond the initial capacity, additional disks were
added or the existing disks upgraded.
2.2
As HC began to implement applications with very large storage
requirements (i.e. Niche Records Management System - RMS,
Automatic Number Plate Recognition System – ANPR), the IT &
Communications department began to implement SAN (Storage Area
Network) systems for these applications. A SAN is a separate system
to the computer server that is dedicated to managing large volumes of
data storage. It means that the data storage is managed separately
providing improved performance, manageability, flexibility and capacity.
2.3
Three SAN systems have been implemented within HC: one to support
RMS; one ANPR and one for general file serving (MS-Word, MS-Excel,
etc.).
2.4
It is clear that the data storage infrastructure within HC has evolved
over time and there is now a requirement to both make more efficient
use of the current investment and also ensure it is placed to deal with
future requirements.
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The Issues
3.1
Growth in Data Storage Requirements
3.1.1 The need for data storage capacity within Police Forces has increased
relentlessly over the past few years and is likely to do so or even
accelerate in the future.
3.1.2 This has been due to a number of factors:
 The requirement to store ever more business data as the Force
moves to intelligence based Policing (e.g. the move to a records
management system – RMS);
 The requirement for retention of data under MoPI guidelines;
 The introduction of new data capture systems such as ANPR
that generate large volumes of data;
 The requirement to retain large volumes of audit data;
 The increasing requirement to store multi-media data (i.e. still
images, moving images, voice, etc.).
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3.1.3 To illustrate this growth, at current growth trends the data stored in the
RMS Live and Disaster Recovery systems currently grow at 1 Gbyte
each per day. The graph below shows that at this rate, the data storage
requirements of these two systems will triple over the next 5 years,
assuming the rate of data capture does not increase.
RMS Live & DR 5 Year Forecast
2000
1780
1560
Threshold 07
Capacity 07
Growth
GB
1340
1120
900
680
460
2007
2008
Year
2009
2010
2011
3.1.4 This trend prediction excludes any increasing requirements to hold
additional multi-media data within the system that are likely to appear
during that time frame.
3.1.5 In addition to the RMS Live and Disaster Recovery systems, similar
capacity growth is required on the RMS Test and Audit systems.
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3.2 Inefficient Use of Current Storage
3.2.1 As the storage infrastructure has evolved over a period of time, the use
of data storage space dedicated to single applications has become
inefficient. Data storage dedicated to one application can not be
switched to be used by a second.
3.2.2 The graph below illustrates the inefficient use of data storage across
157 servers located in the HC computer suite at PHQ.
Hampshire's Total Storage Data in TB
60
50
40
30
20
10
0
Total Capacity
3.3
Used Space
Free Space
Management Issues
3.3.1 Management of multiple separate storage systems has its own
overhead:

Need to purchase more storage capacity even though free
capacity is available on other platforms.

The management costs associated with distributed storage are
much greater than centralised storage; backup, recovery, space
management, performance management and planning in the
event of a disaster recovery are all duplicated across the various
storage systems.

Disk and tape systems are directly attached to an individual
server or SAN and can’t be used by other systems, leading to
inefficient use of hardware resources.
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3.4

Information stored on one system cannot readily be made
available to other users

It is currently very difficult to scale capacity and performance to
meet our changing requirements.

Data spread on multiple small systems is difficult to coordinate
and share for enterprise-wide applications such as our Data
Warehouse and business Intelligence applications.

Our clients and servers are chosen to meet specific application
needs, therefore they run different operating systems, Windows,
Linux, Solaris, HP and so on, and different database software
SQL server, Oracle. Consequently they have different file
systems and different data formats.
Environmental Issues
3.4.1 Storage devices are themselves electronic devices and therefore
require power, UPS (uninterruptible power supply) and air-conditioning.
These are therefore limitations on the storage capacity that can be
installed.
3.4.2 The power supply and UPS in the computer suite at PHQ are currently
being upgraded so that the storage capacity for RMS can be upgraded
and the environmental capacity at the Netley computer suite are already
at their limits.
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Work Underway
4.1
Work is currently underway to address current and future data storage
capacity issues at three levels as follows.
4.2
Work has been undertaken with Niche to implement improved data
compression on the RMS system. This work has resulted in extending
the current available data storage capacity of the live system from end2007 to mid-2008. By mid-2008, additional RMS storage capacity will
be implemented (this is dependant on the electrical work at the PHQ
computer suite).
4.3
Work has been undertaken to develop a technical storage strategy for
HC based on available SAN management technology. The storage
strategy consists of 3 phases:
 Interconnect the existing SAN storage systems. This will allow
spare capacity within the existing storage systems to be pooled
and shared thereby improving the efficiency of our use of spare
capacity.
 Implement virtualised storage technology on the existing SANS.
This allows the entire storage capacity of these systems (both
www.hantspa.org
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
used and spare) to be managed as a single entity, allowing data
to be moved around without the need to bring systems down.
This will improve the efficiency of our use of SAN storage (which
makes up approximately 50% of currently installed storage).
Implement data storage “mirroring” to improve data resilience
and disaster recovery.
4.4
IT&CS are planning to implement the first two stages of this strategy by
the end of the 2007/8 financial year.
4.5
The requirement for a data archive strategy has been identified. MoPI
will determine the Force’s requirements for data retention and deletion.
Data archiving is the moving of data between media of differing cost
and performance depending on its access requirements. For example,
data relating to a recent incident/investigation usually needs to be
accessed frequently, by many people and quickly. It is therefore placed
on high performance & costly storage media. However, as the data
gets older, it needs to be accessed less frequently and speed of
access is less of an issue. Therefore the data can be migrated to
slower cheaper storage systems. Eventually the data may be able to
be archived to tape where access to retrieve data may take days rather
than seconds.
4.6
Data archiving allows the cost of storage to be contained as data is
placed on the appropriate storage system rather than always
implementing expensive high performance systems for all data. The
graph below shows the generic relationship between storage cost and
access performance.
www.hantspa.org
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5
Supporting Information
5.1
As explained earlier, storage has previously been ordered and
implemented as part of single server/application implementations. This
makes it very difficult to separate out the overall cost of storage to the
force. However, the table below does provide some indications of the
costs involved.
Description
Cost
Date
General SAN* (Implementation)
General SAN* (Upgrade)
£96,213
£19,975
Sep-05
Oct-06
RMS live SAN (Implementation)
New RMS Live SAN (Upgrade)
RMS SAN
RMS Test SAN (Implementation)
RMS Test SAN (Upgrade)
£94,854
£99,100
£37,000
£15,300
£8,000
Sep-06
Jun-07
Oct-04
Feb-06
Feb-06
ANPR SAN
£90,000
Sep-04
* The General SAN provides general file storage (documents,
spreadsheets, etc.) to PHQ.
5.2
While the work to install a dedicated power supply to the PHQ
computer suite addresses a number of issues, one of its key drivers is
the ability to power additional systems, in particular the upgrade to the
RMS live SAN. The cost of the new electricity supply is approximately
£305,000.
5.3
The work on storage virtualisation is being managed along with another
piece of work looking at server virtualisation. Server virtualisation is
looking at moving away from single physical servers supporting single
applications to single physical servers supporting multiple applications.
This work is complementary to the storage virtualisation work and will
allow more efficient use and management of server assets.
www.hantspa.org
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Section 100D (Local Government Act 1972) background papers
The following documents disclose facts or matters on which this report, or an
important part of it, is based and has been relied upon to a material extent in
the preparation of this report.
NB the list excludes:
1. published works; and,
2. documents that disclose exempt or confidential information as defined in
the Act.
Title
Storage Strategy
Document v1.1
www.hantspa.org
Location
Available from IT&CS, Hampshire Constabulary
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