# Evaluation of a New-Concept Secure File Server Solution
## 3 Research Methodology
### Methodology of the Performance Tests
#### 3.2.1 Examined Structures  
Preliminary surveys suggested that in typical client-server architectures used in small and medium-sized enterprise (SME) business environments, the file servers are mostly installed with Windows Server operating systems or Unix-like operating systems. Looking at the composition of the clients' OS types, it was stated in our previous survey [18] that the MS Windows 7 x64 SP1 (6.1.7601), MS Windows 10 x64 Pro 21H2, and Ubuntu 22.04.4 LTS operating systems are present in the networks in a huge volume.  
Based on the statements mentioned above, the following measurement structures (TE--Test Environments) were defined for the performance testing, where the ARDS TestServer is a custom-built FreeBSD 13.0 server environment:  
* [TE-01]: Windows 7 client--ARDS TestServer
* [TE-02]: Windows 7 client--Windows 2019 Server
* [TE-03]: Windows 10 client--ARDS TestServer
* [TE-04]: Windows 10 client--Windows 2019 Server
* [TE-05]: Ubuntu 22.04 client--ARDS TestServer
* [TE-06]: Ubuntu 22.04 client--Windows 2019 Server  
In order to obtain the most accurate results, it was important to keep the hardware configurations unchanged on both the server and client sides throughout the tests. The direction of data flow was determined from the client side, and this was where the transfer time was measured for both the read and write tests. The testing of Windows 7 clients was motivated by the fact that, unfortunately, such outdated operating systems are also present in large numbers in the computer pools of SMEs and other service providers.  
The measurements were carried out on the same file server configuration, which typically performs adequately in SME business environments: Intel Xeon 4 Core E-2224G 3.5 GHz processor, 8 GB DDR4 ECC RAM, Apacer AS350X 128 GB SSD (system drive), Gigabyte GP-GSTFS31240 GNTD 240 GB SSD (data drive), and Intel X520-DA2 SFP+ 10 GBE PCI-E dual-port network interface card.  
While designing the physical client-server network, it was taken into account that in SME business environments, data are typically transmitted over Ethernet and SFP interfaces. Consequently, the measurements were run using both 1 Gbit/s and 10 Gbit/s connections. Therefore, it was important that the network card was natively supported by the BIOS and OS, so in this case, the traditional workstation configuration was not used. For the client,the hardware configuration set up was as follows: Intel Core i7-3520M 2.9 GHz processor, 16 GB DDR3 non-ECC RAM, Kingston SSD now V300 120 GB (system+data), Intel 82579 LM Gigabit NIC, Intel X520-DA2 SFP+ 10 GBE PCI-E Dual port NIC.  
The test environment was not designed to scale the network but to investigate the temporal performance of file transfers between different operating systems. The one server-one client architecture is justified by the fact that the proposed file server protection solution focuses primarily on protecting the file server. Having redundant file servers in a network was not considered viable, even approaching the number of workstations communicating with the backup server. For the hardware configuration, we also aimed for a minimal operating environment, which also means that with higher-capacity hardware, performance is certainly no worse than currently under investigation.  
Tests were performed on entry-level business-class hardware because these are typical in the SMA sector. From the aspect of service performance in the comparison phase, hardware platforms do not play significant roles. The performance rates would be approximately the same if we would use high-end blade cluster architectures.