VOL. 4, NO. 6, December 2014 ISSN ARPN Journal of Systems and Software All rights reserved.

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1 Efficiency Solutions for Information Systems 1 Marius Constantin Popescu, 2 Antoanela Naaji 1 Prof., Department of Computer Science, Vasile Goldis Western University of Arad, Revolutiei Blvd., Arad, Romania 2 Assoc. Prof., Department of Computer Science, Vasile Goldis Western University of Arad, Revolutiei Blvd., Arad, Romania ABSTRACT This paper analyzes solutions for improving information systems, using the cost for obtaining high technical performances as a criterion; thus, it partly uses free methods offered by information technology, such as the migration of servers to virtual machines, the implementation of a backup system or the installation of a software router at the expense of more expensive professional solutions. The solutions described can be applied to streamline computer system used within firms or companies, especially those which, due to financial reasons, cannot opt for professional solutions. Keywords: information systems, virtualization, backup, router-firewall 1. INTRODUCTION Through virtualization hardware becomes software, making it possible to run multiple operating systems on the same computer. Through virtualization, the company's critical data and applications are protected, and the time in which the servers are turned off for maintenance is null. The virtualization is designed to move all data on another server in real and virtual time if, for some technical reasons, the server should become nonfunctional. Within the computer systems, two physical disks are used to obtain a logical disk at RAID level 1. The costs are high for this level (the level is also called mirroring [1] because the same data is on two disks), but it has many advantages. The biggest advantage of RAID level 1 is data integrity, as in the case of failure in one disk the information is not lost. After replacing the failed disk, the data is also cloned on the new disk. Another advantage is the increased performance in reading data. Usually, two identical disks (same brand, capacity, rpm, etc.) are recommended for this RAID level. When using two different disks, the logical disk will have the properties of the least powerful disk. Some RAID controllers allow replacing the defective disk without shutting off the system. This feature is called hot swap. When a hot swap controller is used, a third backup disk must be installed. The only downside to hot swap is that the backup disk will be on all the time, and if it is a hard disk, it will rotate even if no data is written/read. One of the advantages of a virtual machine is that it can make a snapshot before any update or change. Thus, should any updates or changes fail, the system can be restored to the initial state of the snapshot. Basically, the snapshot function saves the state of the server at the time of initiating the snapshot and it can instantly return to its original state. From that moment on, any changes will be recorded in a temporary file. The more changes occur in the server, the more the size of that temporary file will increase. When updates or changes are successful and returning to the initial state is not desired, that snapshot is deleted, and the data in the temporary file is updated on the server. 2. FORMULATION OF THE PROBLEM The aim of this paper is to find a solution to improve a computer system consisting of two physical servers, which were running the operating systems Windows Server 2003 Standard edition and Windows Small Business Server 2011, with the following specifications: Dell Power Edge Windows Small Business Server 2011 (processor (Intel (R) Xeon (R) CPU GHz), RAM (32GB) and HDD (450 GB 1xSAS)) and Dell Power Edge Windows Server 2003 Standard Edition (processor (Intel (R) Xeon (R) CPU X GHz), RAM (8GB) and HDD (600 GB 1xSAS)). In the initial configuration, the backup was performed from the server interface under Windows. In case of hard disk failure, the backups and data could not be recovered. A physical router was used before the upgrade. Analyzing the offers available on the market, the prices for the VMware professional virtualization solution are presented in Table 1. VMware vsphere 5 Essentials licenses can be installed on a maximum of three physical servers with up to two processors / server [2]. 143

2 Table 1: Professional virtualization solution offers on the software market. Code Description Amount Unit Price VS5-ESP-KIT-C VMware vsphere 5 Essentials Plus Kit for 3 hosts (Max 2 processors per host) 1 2,834.7 EUR VS5-ESP-KIT- G-SSS-C VS5-ESP-KIT- 3G-SSS-C A support plan for 1 or 3 years must be purchased. Basic Support/Subscription VMware vsphere 5 Essentials Plus Kit for 1 year Basic Support/Subscription VMware vsphere 5 Essentials Plus Kit for 3 years Some professional backup solutions are given in Table 2, noting that the Acronis backup solution for VMware, which costs 399 USD, is also available EUR 1 1,801.8 EUR Table 2: Professional software backup solution offers on the software market Code Description Amount Unit Price V-ESSSTD-VS-P Veeam Backup Essentials Standard 2 socket bundle for VMware (Backup & Replication Standard + Veeam ONE) EUR A solution for hardware router / firewall on the market costs, for example, between 140 EUR and 260 EUR. Analyzing the necessary cost offered by the market to improve the information system described above, a conclusion has been reached that it would be much more economical to apply improving software methods. 3. PROPOSED SOLUTION Migration from physical server to virtual machine was chosen for safety reasons, in case of failure in any physical component. Since other, energyconsuming hardware equipment is no longer necessary, the budget of companies using this method becomes efficient. Likewise, RAID 1 (mirror) was chosen for the configuration of storage media [3]. The virtualization solution implemented on the two servers was freeware offered by VMware. This free version does not have backup support, but we used a free alternative to the backup. The operating system of the virtual machine is VMware vsphere Hypervisor (ESXi). The management and configuration of the virtual machines is done, via network, from any computer, through the vsphere Client graphical user interface (very friendly and intuitive). The management can also be done directly from the server, but the text interface is much more complicated and not at all intuitive. For a backup solution we chose a refurbished additional server, with the following specifications: processor (Intel (R) Xeon (R) CPU E GHz), RAM (8GB) and HDD (2TB 4xSATA - RAID 10). Its only role is to store backups from both virtual machines. The backup takes about four hours and a half and is done every day at 1:00 a.m. from Tuesday to Saturday. A free operating system, Open filer [4], was chosen for this server and configured to provide an NFS (Network File System) partition for the backup. Since the backup server requires high capacity and very good data safety, RAID level 10 (mirror + stripe) was used, which utilizes four 2TB logical disks. The logical disk capacity is 4 TB. An alternative was to use RAID level 5, in which case the logical disk capacity would be 6 TB. For safety reasons and from the experience of other users, 2 TB were sacrificed in favor of RAID 10. RAID 10 requires a minimum of 4 physical disks for implementation, placing two RAID 1 matrices in RAID 0. Using this configuration, we benefit from data safety, redundancy, as well as very good performance. It is also possible to use two RAID 0 matrices in RAID 1 into a RAID 0+1 configuration, but RAID 10 has a much better tolerance to failures, accepting the failure of several disks. RAID 0+1 supports the failure of one disk, while RAID 10 supports the failure of two discs (one from each RAID 0). From the web interface of the Open filer operating system, the MAC address of the two servers is set, so that the NFS partition cannot be used by other terminals. For fast backup, it is necessary to change of the input/output mode from synchronous (sync) to asynchronous (async). The difference between sync and async is observed in the backup script performance. By selecting async, 1TB backup is written in 4:30 hours, while using the sync method, it is written in 20 hours. Synchronous and asynchronous are two different methods of data transmission in a network. The async method uses two different signals [5], one signal indicating the other signal that another bit of information is ready for transmission. The sync method uses a single signal and a pulse from the local clock, indicating when the next bit is ready for transmission. The free backup solution is from MagikMon [6]. Thus, the backup program was installed on SBS2011 and was scheduled to perform backups every day from Tuesday to Saturday, from 01:00 a.m. This action means that every night at 1:00 the backup program is running, connecting to virtual machines via SSH (secure shell) and performing the backup. 144

3 (a) (b) Fig 1: The interface of the ESXi backup operating system The Actions tab features the program being run, including configuration files (Figure 1). Specifically, the backup is performed as follows: At 1:00 a.m. the backup program is run from the task scheduler. This accesses the configuration file, logs on to the virtual machine interface, gives the command to make a snapshot, then copies the virtual machine files onto the backup server. Figure 2 describes some important lines in the configuration file that sends commands via SSH. [VMWARE_JOB_5] host= port=22 login=root password=******* local=c:\magik\vmware remote_temp=/tmp script=ghettovcb.sh global_conf=ghettovcb5.conf vm_list=plastec_2003_server2 VM_BACKUP_ROTATION_COUNT=3 (a) 145

4 (b) Fig 2: Explanatory illustration of backup The lines in Figure 2a are extracted from the configuration file of the virtual machine with Windows Server The last line represents the number of backups that remain on the server. Figure 2b shows the structure of folders on the backup server. It can be seen that the backups are saved by date and time (Figure 4). For example, the first backup was performed on , whereas on and the backup was not performed because these days are in the weekend and no major changes occur on servers. In performing the next backup, a snapshot will be made of the virtual machine, its files will be copied on the backup server, and after the operation is complete, the oldest backup will be deleted. In this case, the backup will be deleted. Besides the backup function, the MagikMon solution has an notification option. Thus, mail server data was set in the.ini file, and after each backup reports are received by . Thus, the message subject features an OK or ERR text, as applicable. These reports also contain the logs in which it can be seen why a backup failed (Figure 3). Therefore, it is easy to detect the area where a problem occurs. (a) 146

5 (b) Fig 3: Explanatory illustration of obtained reports. The improvement of the information system was dropped by attaching a physical router and installing a software router (pf Sense) which is free and which, in addition to multiple configuration possibilities, also acts as a firewall [7]. A few ports were opened from the software router interface (Figure 4). Fig 4: The software router interface The first position, SIP Trunk, is the port used by the telephone system for incoming calls. The IP address and the source port are specified, while the other ports can be accessed from anywhere. The second position allows access to the company website hosted by SBS2011 (IIS). A third position opens the port 443, and the employees can check the mail from any web access terminal. The last position opened the SMTP port for mail. 4. CONCLUSION Technical support and other functions that paid professional versions of virtualization solutions (eg VMware) possess can be dropped, thus saving money (a minimum of EUR) with the free solution described in this paper. The backup and recovery functions are not available in the free version, but it has been shown that a much less expensive alternative can be implemented. The backup solution uses a free operating system, Open filer, providing an NFS partition and an application from Magic on which connects to the virtual machine via SSH, makes a snapshot and copies the current state of the virtual machine. The backup server is refurbished and uses 4 2TB HDDs. A refurbished server is chosen for the router / firewall solution. The router / firewall application does not require huge resources to run properly. In this paper, the operating system is pf Sense and has all the functions that a much more expensive professional router / firewall has. Before virtualization there was a single hard disk that could malfunction at any time, so the data on the server could be recovered with great difficult or, in some cases, not at all. 147

6 REFERENCES [1] T. Rhodes, RAID1 Mirroring. Chapter 19. GEOM: Modular Disk Transformation Framework, available at: [2] *** VMware vsphere 5.5. Documentation Center, Centre, available at: 55/index.jsp?topic=%2Fcom.vmware.vsphere.stora ge.doc%2fguid-99bb81ac e5-bf67-8d43647fad31.html [3] M.C. Popescu, Utilization des ordinateurs, Universitaria Publishing, Craiova, [4] L.M. Surhone, M.T. Tennoe, S.F. Henssonow, Open filer. Betascript Publishing, Mauritius, [5] M.C. Popescu, Telecommunication, Universitaria Publishing, Craiova, [6] *** MagiKmon, available at: [7] M. Williamson, pf Sense 2 Cookbook, Packt Publishing,