Simulation Tool Frequently Asked Questions

For a description of how iModel works and the preservation workflows it models, please look at our new iModel documentation

1. What is iModel?

iModel is a software used to simulate the operation of real archive systems.

The tool consists of a configuration wizard used to setup custom model configurations and interactive simulation interface. This interface allows to monitor the operation of the model under various peformance criteria as well as allows to dynamically adjust the operation of the model at run-time.

1.2 What operating systems can I use to run iModel?

The software is provided as pre-build packages for Windows, Mac and Linux. Full Java source is also available on the download page for those users running alternative operating systems.

1.3 How to install and run iModel on Windows?

Installation process on Windows is automated through the installer that performs all the necessary installation steps. Once the installation process is completed, the tool can be found under the following location: Start->All programs->IT Innovation Centre.

1.4 What kind of archive systems can we simulate using iModel?

iModel allows you to simulate archive systems that consist of following system components: storage system, access queue and ingestion queue. Depending on the number of concurrent storage systems the tool can be run in three modes: single storage system (single storage system with access and ingestion queues), two-storage system model (two storage systems with access and ingestion queues) and three-storage system model (three storage system with access and ingestion queues).

1.5 How to run archive system simulation using iModel?

Following steps are required to intialize the simulation:

  • Selection of system model architecture used for simulations (single, two or three-storage). These options are provided on the main simulation page.
  • Selection of a particular model template the configuration of which will be used during simulation (accessible through a drop-down list for each model architecture).
  • (Optional) configuration and adjustment of the selected template to match the configuration properties of the simulated model. To configure the template, select the template and press Setup button next to it. This will initialize the Configuration Wizard.
  • Initialization of the model with selected configuration template. To run the model, press Run model button. This will initialize the model.

1.6 Can I create my own archive system configuration and use it during simulation?

Yes. Interactive Model Configuration Tool provides the capability to create custom, user-specific model configurations that can be created, stored and reused during model simulations.

1.7 What configuration options are provided by iModel?

iModel provides a set of configuration options that allow to produce custom user-defined model configurations. To allow fine grained configuration of the archive system the tool provides Configuration Wizard that allows to create custom configurations of individual system components such as ingestion and access queue or storage system. These templates can be then combined to produce user-specific model configurations.

1.8 What is the role of 'Include startup cost' checkbox located in cost configuration panel?

If startup cost is not considered, the is no startup cost associated with the initial deployment of assets. If startup cost is taken into account, following costs contribute to it: data transfer cost and service requests cost.

1.9 Simulation crashes and I get 'out of memory' information. What is causing the problem?

You may experience out of memory error if the memory size allocated to run the model is insufficient. This may happen in situations when you are simulating large number of files (over 1 million) and Java heap allocation size is too small to handle this. To fix this problem, please adjust heap allocation size parameter located in 'configuration.txt' startup file.