Server Requirements

Owned by René Pape
Last updated: 25 Jun 2019

The DVI System Server is the key component of a DVI System deployment.

The hardware requirements are the recommended minimum size of the hardware, and no absolute minimum requirements can be given as they will depend on the patience of the users and the composition of the disaster and distributed workload. In example, if all PM examinations are being recorded digitally at the morgue, you will have a higher simultaneous load as if all data entry is being done by a smaller group of operators. Also, the size of image attachments is determined by the photographic and XRay equipment and the number of photos that is relevant to the disaster.

This system has the same general requirements as all other database-oriented software, a machine for SQL Server with as much RAM and as fast disks as you can afford (with the size necessary for your anticipated number of cases and especially attachments) and a machine for IIS and business layer (web services) with RAM equivalent to the anticipated simultaneous sessions and CPU to support the matching load. If you have a heavy DNA load, just add another Application Server.

We assume that matching (automated everything against everything searches) is only performed during off-peak hours, such as at night time

Future requirement

With installation of DVI System International version 6, minimum software requirements are Windows 10 for Windows workgroup deployments, Windows Server 2016 for Server deployments  and SQL Server 2016 SP1 as database server.

Also, the DVI6 application server parts are more memory-intensive and can utilise more CPU cores. We are experimenting with ways to delegate matching to relatively cheap Windows machines with a lot of RAM instead of a very expensive multi-CPU SQL Server.

National DVI Centre

A large DVI centre can handle 50.000 files of Missing Persons and/or Unknown Bodies and 150 simultaneous users

Hardware
SQL Server

IBM x3650M4 rack server (example)
2 * 4 core CPU
10 * 600 GB disks in RAID 10 configuration
24 GB RAM

Application Server

IBM x3650M4 rack server (example)
2 * 6 core CPU
4 * 600 GB disks in RAID 10 configuration
96 GB RAM

Software

Windows Server 2012R2 or later, Standard or Datacenter
Microsoft SQL Server 2008R2 or later, Standard or higher. Clustering or failover is not part of our advice/support options, but has proven to work if you know what you are doing.

Regional DVI Center

A regional DVI center can handle 10.000 files of Missing Persons and/or Unknown Bodies  and 75 simultaneous users 

Hardware
Combined SQL- and Application Server

IBM x3650M4 rack server (example)
2 * 6 core CPU
6 * 600 GB disks in RAID 10 configuration
96 GB RAM

Software

Windows Server 2012 R2 Standard or Datacenter
Microsoft SQL Server 2008 R2 -, 2012 - or 2014 Standard or higher. Clustering or failover is not supported in all configurations.

Local DVI Center (or Site server)

A local DVI center can handle 2.000 files of Missing Persons and/or Unknown Bodies  and 25 simultaneous users 

Hardware
Combined SQL- and Application Server

1 * 6 core CPU
4 * 600 GB disks in RAID 10 configuration
16 GB RAM

Software

Windows Server 2012 R2 or later, Essentials or Standard
Microsoft SQL Server 2008 R2 -, 2012 - or 2014 Express or higher. Clustering or failover is not supported.
With the Express edition, there is a 10GB* maximum database size which effectively limits the storage for attachments (images, documents etc.), so you could be forced to upgrade to a Standard edition if you don't limit attachment sizes.

DVI Workgroup

A DVI workgroup can handle 500 files of Missing Persons and/or Unknown Bodies and up to 8 simultaneous users 

Hardware
Combined SQL- and Application Server

1 * 4 core CPU (i.e. a laptop with Intel i7-4702MQ)
512 GB disk, preferably SSD
8 GB RAM, preferably more if not using SQL Express.

Software

Windows 7 SP1, 8 or 8.1 Pro, 10 Pro 64bit or 32bit (64bit recommended), with the Internet Information Services components installed.
Microsoft SQL Server 2008 R2 or later,  - Express* or higher, SQL 2016 Express recommended for a start.
With the Express edition, there is a 10GB maximum database size which effectively limits the storage for attachments (images, documents etc.). The Express editions also limits the CPU and memory utilisation, but not to levels that significantly affects a few simultaneous users.

If you are unsure about the actual number of users in your DVI Workgroup, you could install a Windows Server license on the laptop.

If database queries proves to be a bottleneck, you may choose to upgrade the SQL Server to a non-express version.


It is important to understand the limitations of using a desktop operating system like Windows 7, 8 and 10 as a server. Microsoft has implemented some strict limitations on concurrent requests in Internet Information Server on these platforms (varying from 3 to 10 simultanous requests depending on OS edition), so you will experience, that just adding one more workstation doesn't just make the system gradually slower, but may change the response time from i.e. 0.5 seconds to 30 seconds per request.