Network File System Server Research Articles

Booting of Diskless Workstation

This paper focuses on proposing a system for centralization of the IT infrastructure by building upon the concept of Diskless Booting. The client stations are configured to boot over an existing network using the Network Boot. The Client Station lacks an actual Hard Drive, which is responsible for storing the boot files and other necessary files. It consists of other hardware excluding the Hard Drive such as, RAM, Processor, etc. The network consists of DHCP (Dynamic Host Configuration Protocol) server which assigns IP addresses to several client stations connected. The NIS (Network Information Service) server stores the login credentials of all the users, enabling the users to login from any client station without any restrictions. The NFS (Network File System) server makes the files available for the user, even on the absence of local secondary storage. Security is ensured by SHA (Security Hash Algorithm), which encrypts the sensitive data by creating the hash values. Individual ports and services can be kept secured by using the Firewall service. The open source Cockpit Tool provides a GUI with which the administrator can conveniently carry out several admin-oriented tasks, such as memory management, user management.

Enhancing Data Transfer Performance Utilizing a DTN between Cloud Service Providers

The rapid transfer of massive data in the cloud environment is required to prepare for unexpected situations like disaster recovery. With regard to this requirement, we propose a new approach to transferring cloud virtual machine images rapidly in the cloud environment utilizing dedicated Data Transfer Nodes (DTNs). The overall procedure is composed of local/remote copy processes and a DTN-to-DTN transfer process. These processes are coordinated and executed based on a fork system call in the proposed algorithm. In addition, we especially focus on the local copy process between a cloud controller and DTNs and improve data transfer performance through the well-tuned mount techniques in Network File System (NFS)-based connections. Several experiments have been performed considering the combination of synchronous/asynchronous modes and the network buffer size. We show the results of throughput in all the experiment cases and compare them. Consequently, the best throughput in write operations has been obtained in the case of an NFS server in a DTN and an NFS client in a cloud controller running entirely in the asynchronous mode.

A Low Cost Two-Tier Architecture Model for High Availability Clusters Application Load Balancing

This article proposes a design and implementation of a low cost two-tier architecture model for high availability cluster combined with load-balancing and shared storage technology to achieve desired scale of three-tier architecture for application load balancing e.g. web servers. The research work proposes a design that physically omits Network File System (NFS) server nodes and implements NFS server functionalities within the cluster nodes, through Red Hat Cluster Suite (RHCS) with High Availability (HA) proxy load balancing technologies. In order to achieve a low-cost implementation in terms of investment in hardware and computing solutions, the proposed architecture will be beneficial. This system intends to provide steady service despite any system components fails due to uncertainly such as network system, storage and applications.

Using eager strategies to improve NFS I/O performance

Typical network file system (NFS) clients write lazily: they leave dirty pages in the page cache and defer writing to the server. This reduces network traffic when applications repeatedly modify the same set of pages. However, this approach can lead to memory pressure, when the number of available pages on the client system is so low that the system must work harder to reclaim dirty pages. We show that NFS performance is poor under memory pressure and present two mechanisms to solve it: eager writeback and eager page laundering. These mechanisms change the client's data management policy from lazy to eager, in which dirty pages are written back proactively, resulting in higher throughput for sequential writes. In addition, we show that NFS servers suffer from out-of-order file operations, which further reduce performance. We introduce request ordering, a server mechanism to process operations, as much as possible, in the order they were sent by the client, which improves read performance substantially. We have implemented these techniques in the Linux operating system. I/O performance is improved, with the most pronounced improvement visible for sequential access to large files. We see 33% improvement in the performance of streaming write workloads and more than triple the performance of streaming read workloads. We evaluate several non-sequential workloads and show that these techniques do not degrade performance, and can sometimes improve performance.

Implementation of a stackable file system for real-time network backup

We propose a backup system based on a stackable mirroring file system, general-purpose mirroring file system (GMFS). This file system mirrors data in real-time on the file system layer. It uses the typical network file system (NFS) and backs up data to one or more NFS servers. Therefore, an existing empty resource can be used. It is necessary to backup data to two or more servers in case a backup server fails. Moreover, the throughput of read and write operations has been improved by adopting a method of calling a system function inside NFS. Experimental results shows that the throughput of read and write operations of GMFS is 2.4 times faster than that of conventional mirroring file systems. In addition, even when the number of backup servers increases, the decrease in throughput is small.

Seamless Access to Decentralized Storage Services in Computational Grids via a Virtual File System

This paper describes a novel technique for establishing a virtual file system that allows data to be transferred user-transparently and on-demand across computing and storage servers of a computational grid. Its implementation is based on extensions to the Network File System (NFS) that are encapsulated in software proxies. A key differentiator between this approach and previous work is the way in which file servers are partitioned: while conventional file systems share a single (logical) server across multiple users, the virtual file system employs multiple proxy servers that are created, customized and terminated dynamically, for the duration of a computing session, on a per-user basis. Furthermore, the solution does not require modifications to standard NFS clients and servers. The described approach has been deployed in the context of the PUNCH network-computing infrastructure, and is unique in its ability to integrate unmodified, interactive applications (even commercial ones) and existing computing infrastructure into a network computing environment. Experimental results show that: (1) the virtual file system performs well in comparison to native NFS in a local-area setup, with mean overheads of 1 and 18%, for the single-client execution of the Andrew benchmark in two representative computing environments, (2) the average overhead for eight clients can be reduced to within 1% of native NFS with the use of concurrent proxies, (3) the wide-area performance is within 1% of the local-area performance for a typical compute-intensive PUNCH application (SimpleScalar), while for the I/O-intensive application Andrew the wide-area performance is 5.5 times worse than the local-area performance.

Global namespace for files

We propose a name service that enables construction of a uniform, global, hierarchical namespace, a key feature needed to create a file-system grid. Combined with other grid replication and location-lookup mechanisms, it supports independence of position for users and applications as well as transparency of data location in a scalable and secure fashion. This name service enables federation of individual files as well as file-system trees that are exported by a variety of distributed file systems and is extensible to include non-file-system data such as databases or live data feeds. Such a federated namespace for files can be rendered by network file servers, such as NFS (Network File System) or CIFS (Common Internet File System) servers, proxies supporting the NAS (network-attached storage) protocol, or grid data service interfaces. File access proxies, which handle protocol translation, can also include caching and replication support to enhance data access performance. A uniform namespace with global scope and hierarchical ownership allows sharing file data between and within organizations without compromising security or autonomy.

Caching in the Sprite network file system

Caching in the Sprite network file system