Server Requirements

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

The DVI System comprises four or more logical servers which can be deployed to one or more physical or virtual servers. You will deploy IIS-Server, DVI api-server, IdentityServer4 and SQL Server. The DVI api-server internally also spawns the first job-server and a signal-R hub/server.

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 a reasonable amount of 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 (api and identity services) with RAM and CPU equivalent to the anticipated simultaneous sessions and search- and matching load. If you have a heavy or repeating matching load, just add more Job Servers, and the matching load will be distributed automatically. Job servers may be relatively cheap non-server PC’s with large amounts of RAM and CPU-cores, and from a cost perspective, they don’t count towards SQL CPU Core licensing, they also don’t need to be fancy expensive server hardware as they are fault tolerant and the api server just moves the load to another PC if one dies.

Multiple job servers are not supported in the early release versions

When deploying to a virtualised- or cloud-environment, specific CPU requirements doesn’t really make sense, and you should be prepared to dynamically monitor and scale the server VM’s as necessary based on the current disaster situation and number of involved Officers.

We assume that matching (automated everything against everything searches) is only performed during off-peak hours, such as at night time, unless matching is off-loaded to multiple job servers.

National DVI Centre

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

SQL Server
Hardware

HP E ProLiant DL380 Gen10 rack server (example)
1 x Intel Xeon Gold 5222 / 3.8 GHz (3.9 GHz) (Quad-Core)
10 * 600 GB disks in RAID 10 configuration
32 GB RAM

Software

Windows Server 2016 or later, Standard or Datacenter
Microsoft SQL Server 2017 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.

Application Server
Hardware

HP E ProLiant DL380 Gen10 rack server (example)
2 x Intel Xeon Gold 5222 / 3.8 GHz (3.9 GHz) (Quad-Core)
4 * 600 GB disks in RAID 10 configuration
96 GB RAM

Software

Windows Server 2016 or later, Standard or Datacenter
Microsoft SQL Server 2017 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.

Optional Job Server

The optional Job Server can read jobs from the Job Queue on the SQL Server and run the Jobs.

Hardware

To be defined

Software

Windows 10 Pro 64bit
Windows Server and SQL Client Access License (or CPU licensing on servers)

Regional DVI Center

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

Hardware

1 * HP E ProLiant DL380 Gen10 rack server (example)
2 * Intel Xeon Gold 5222 / 3.8 GHz (3.9 GHz) (Quad-Core)
8 * 600 GB disks in RAID 10 configuration
96 GB RAM

Software

Windows Server 2016 or later, Standard or Datacenter Microsoft SQL Server 2017 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.

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

1 * 6 core CPU
4 * 1000 GB disks in RAID 10 configuration
32 GB RAM

Software

Windows Server 2016 or later, Essentials or Standard
Microsoft SQL Server 2017 or later, Express2 or higher. Clustering or failover is not supported.

DVI Workgroup

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

Hardware

1 * 4 core CPU Laptop
512 GB disk, preferably SSD
16 GB RAM, preferably more if not using SQL Express.

Software

Windows 10 Pro 64bit1, with the Internet Information Services components installed.
Microsoft SQL Server 2017 or later, Express2 or higher. SQL 2019 Express recommended for a start.

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


1 It is important to understand the limitations of using a desktop operating system like Windows 10 as a server. Microsoft has implemented some strict limitations on concurrent requests in Internet Information Server on Windows 10, 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.

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