## 2 Related Works
### P2P Protocol for System Deployment
[34], such a BT client can significantly improve the overall Internet resource utilization without degrading users' downloading performance. Compared with several prevalent BT clients, the TopBT can reduce download traffic by about 25% while achieving a 15% faster download speed. The BT-based solution was also used to deploy the image of virtual machines in cloud computing, [PERSON] and [PERSON] [53] proposed a BT-based solution that can cache the virtual machine images in the local computers to be deployed. Such a system can reduce the transfer time when a large number of requests are raised. [PERSON] et al. [54] also used the BT protocol to accelerate the image delivery to the cloud-based environment with a large number of virtual machines. In addition, [PERSON] et al. 's solution [54] was integrated into the Filesystem in the Userspace (FUSE) software interface through a message-driven piece selection scheme. Thus, virtual machines and requested services can be enabled within the required time. [PERSON] [55] also implemented a BT-based solution to distribute the images of virtual machines to computers. By gluing some freely available applications and their own scripts with the BT protocol, the completion time was reduced to less than one-sixth. As for the bare-metal provisioning based on the BT protocol, [PERSON] et al. [56] introduced a BT-based solution that aims to achieve the efficiency, scalability, independence, and reliability (ESIR) of image transfers in mass deployment. Comparing the performance of both the multicast and ESIR-based solution, the ESIR-based system is more reliable, whereas the performance of image distribution is higher. [PERSON] et al. [57] designed and implemented a BT-based solution in the Kadeploy3 software to perform bare-metal provisioning. The software has been used intensively on the Grid'5000 test-bed since the end of 2009. Approximately 620 different users have performed 117,000 deployments. On average, each deployment involved 10.3 nodes. The largest deployment involved 496 nodes. Thus, Kadeploy3 is particularly suitable for large-scale clusters. [PERSON] and [PERSON] [58] also proposed system architecture utilizing the P2P protocol. The throughput can be increased while multiple OS are deployed. According to [PERSON] and [PERSON] [58], a system using the BT-based solution is much more efficient when deploying a larger number of machines than the performance that can be achieved by the traditional unicast mechanism. [PERSON] and [PERSON] [59; 60] proposed adding a BT solution to the original OpenStack Ironic project in order to shorten the bare-metal provisioning time. They embedded the BT functionality directly on the storage nodes. The BT functionality is right on top of the OpenStack Swift Application Programming Interface (API). The image is downloaded directly from the object store. Basically, the process consists of three steps: (1) update the OpenStack with appropriate drivers and patches; (2) create the torrent file and associate it with an image; and (3) boot the new node using the torrent-based image. The node will be able to use both peers and the object storage to download the image as well as share the downloaded data with other peers. The BT solution requires 15 minutes to provide 90 nodes with a three-GiB image. Compared to the solution based on the standard OpenStack Ironic, which took one hour to provide 15 nodes with a three-GiB image, the BT-based solution is more efficient. Based on the analytic results by [PERSON] and [PERSON] [59; 60], the BT-based solution requires only 25% of the provision time as the standard OpenStack solution, even when the number of nodes to be deployed is six times more. However, existing research related to bare-metal provisioning using the BT protocol has focused primarily on the efficiency, scalability, and reliability of the systems. To the best of the authors' knowledge, no existing study has tried to address the issue related to the shortage of temporary storage.