AIMS AND SCOPE
NRENs and other academic organisations are currently using, building or planning to build so-called low-cost storage infrastructure. Aim of this work is to help the system designers in understanding the real costs of the storage systems and making educated decisions related to choosing the hardware and software platforms.
TCO calculator enables analysing the storage infrastructure costs including the hardware investments costs as well as operational costs including energy, maintenance and data center costs. It also calculates and simulates overal system parameters such as system throughput, IOPS etc.
At the moment TCO calcuator cosinders the low-cost storage systems based on disk servers. It takes into account costs and parameters resulting from the server platform used, HDD and SSD drives applied as well as software defined storage software specifics (now mainly Ceph, to be extended in future).
The content and organisation of the TCO calculator is a result of the discussion among NRENs that started during the TF-Storage meeting in Vienna (February 12-13, 2015) and teleconferences organised afterwards. Notes from the teleconferences are (or will be) included in the child pages.
HOW TO USE THE TCO CALCULATOR.
TCO calculator is provided as the excel sheet to be used offline. At some point we will perhaps prepare an online tool.
You can get the tool from here: TCO_calculator
For Excel users: sometimes Excel report the file as 'broken' and asks if it should try to 'repair' it - please answer yes if you trust us 
You may specify the basic system parameters on the single sever landing page. They include sever platform, type of the HDD and SSD disks used as well as the data redundancy level and access pattern planned in the system.
You may also analyse multi server configuratons using a dedicated tab, for instance simulate various sizes of your low-cost storage system and associated costs.
Servers, HDD disks and SSD parameters can be added to the tabs that include known server platforms and their components. These lists should be extended so that they reflect all platforms and components known to the NRENs. We count on your contribution to make the tool comprehensive!
Computations related to power usage, capacity and performance are based on several parameters and assumptions, collected in the parameters tab.
The remaining tabs contain the models and formulas for calculating the system capacity, performance, CAPEX and OPEX cost etc.
Temporarily network related costs (e.g. cost of the cluster interconnect switches, network uplinks) are not considered. This will be improved in the next versions.
The major change in the current version vs the previous ones is distributing the calculator into several tables. Based on this organisation, partners will be able to work independently on particular aspects of the calculator, e.g. IOPS modelling or power consumption calculations.
PLANS and ROADMAP
Hardware aspects and parameters are simulated based on the catalogue values mainly. The parameters and assumptions adopted need to be verified by real life experience and measurements.
Models for simulating the power usage, MB/s and IOPS performance are relatively simplistic. We should perhaps work on improving these models based on the existing heuristics supported by real life relatonships and values collected by NRENs. Again! we need you contribution here!
Efforts will be also put into including the storage software specifics in the simulations.
It is also planned to consider traditional disk array- and tape-based systems in addition to low-cost disk server platforms. This will enable comparing the various approaches for implementing the storage services.
FEEDBACK
As the TCO is a work in progress we would appreciate ANY kind of feedback. Therefore if you like it or dislike it or have an idea of improvement or extension or you are willing to contribute to it, please contact us on the storage@terena.org mailing list.