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1 Strategic Communications SSANS in Small to Medium Size Businesses Analysis: Simplifying SAN administration through host-based wizardst: Prepared for:

2 Analysis: Simplifying SAN administration through host-based wizards Author: Jack Fegreus, Ph.D. Technology Director Strategic Communications March 30, 2004 Prepared for QLogic Corp. Jack Fegreus is Technology Director at Strategic Communications, which consults with a number of independent publications. He currently serves as Editorial Director of Open magazine, Labs Director of HP World and contributes to InfoStor. He has served as Editor in Chief of Data Storage, BackOffice CTO, Client/Server Today, and Digital Review. Previously Jack served as a consultant to Demax Software and was IT Director at Riley Stoker Corp. Jack holds a Ph.D. in Mathematics and worked on the application of computers to symbolic logic.

3 Table of Contents Table of Contents Executive Summary 04 Assessment Scenario 06 The Out-of-Box Experience 07 SAN Lifecycle Management 11 Conclusions 14 03

4 Executive Summary Executive Summary What changes the equation in favor of SAN deployment at SMB sites is the introduction of technology that simplifies the deployment and management of a SAN throughout its entire life cycle. Technology innovations, along with a new demand-driven consumer market, have radically changed the way large enterprises architect IT operations. These drivers are now emerging as powerful forces for change in the smallto medium-sized business (SMB) arena. Key drivers for change are: Rise of the web as a 24x7x365 transactional environment Use of customer relationship management (CRM) software to track and direct sales efforts Emergence of high-end, rack-mounted servers dedicated to singletask functions Growing awareness at the corporate-officer level of the value of company data and risks posed by backup and security vulnerabilities 04 To meet the imperatives of this new business environment, IT departments in SMB enterprises are frequently structuring their IT services around three to four servers dedicated to single strategic tasks: A Windows domain controller to provide file, print, and single login services for desktop and laptop PCs A Linux web server An server A database server Out of this new IT environment, the dominant cost driver has become data storage. While the capacity of disk drives has increased exponentially, the traditional method of employing dedicated SCSI-based storage devices on each host along with the need to provide enhanced data security have weighed against any savings and have actually driven costs steadily upward. The reason for the escalation in storage cost-centers is IT s near-religious use of RAID arrays to provide servers with added data security. While

5 Executive Summary RAID arrays do provide mathematical assurance in eliminating single points of failure, RAID schemes require multiple drives, hot-spare drives, and in some cases duplicate drives for mirror sets. In addition, most sites implement RAID functionality through dedicated, expensive RAID controllers that incorporate on-board cache and battery backup. In such an environment, large-capacity drives become a source of overcapacity rather than a source of savings. At large enterprise sites where total disk capacity is measured in tens, if not hundreds, of terabytes, the storage savings potential also totaled up orders of magnitude greater than SMB sites. As a result, the notion of virtualizing physical disk storage over a fiber optic network, dubbed a storage area network or SAN, proved particularly appealing much earlier. While the costs and complexity of early SANs were staggering, the sheer volume of storage in use at these sites made it financially attractive to be a SAN pioneer. The generation gap between today s SAN technology and the first-generation SANs of the large enterprise data center is huge. SMBs can now take advantage of unprecedented innovation and affordability. The introduction of low-cost disk drives, with capacities of around200 GB, makes it very easy to build a 1-TB RAID array. While only a few of today's SMB servers require 1TB of storage, many SMBs are finding that their overall storage needs are rapidly approaching the multiple-terabyte level. 05 While large-capacity drives provide an opportunity for cost savings, they don t always mean lower total cost of ownership (TCO). The costs associated with configuration and maintenance of traditional SAN topologies makes it nearly impossible for a minimally-staffed IT organization to realize any operational savings. And some SMB environments will never grow to use all the utilization capacity of the larger drives in a SAN installation. What changes the equation in favor of SAN deployment at SMB sites is the introduction of technologies that simplify the deployment and management of a SAN throughout its entire lifecycle. To this end, QLogic Corporation commissioned Strategic Communications to assess the new SAN technologies introduced with QLogic s SANbox 5200 stackable switches. In this white paper, we examine the introduction of wizards in host-based rather than device-based configuration software to simplify SAN installation and management.

6 Assessment Scenario Assessment Scenario We were able to go from boxed HBA and switch equipment to a fully-functional, fault-tolerant working SAN in just 30 minutes. For this assessment, Strategic Communications examined the ease with which an initial working SAN fabric could be configured and then later extended using QLogic SANbox 5200 switches and SANbox Manager, a host-based application program included with each switch. The target user was considered to be a seasoned systems administrator who had no previous experience with SAN design or management. The target environment consisted of three servers running Windows Server 2003 and Linux that would access logical disk drive partitions from a central RAID storage system, as well as a central shared tape drive. The business constraint for our test SMB site was the need to provide guaranteed 24x7x365 access for all systems. In particular, we set up a test environment using three Intel Xeon based servers sporting PCI-X expansion slots. These servers came from three different manufacturers: a Dell PowerEdge 4400, an HP ProLiant ML 350 G3, and an Appro 2400Xi. The Dell and HP servers were configured to run Windows Server 2003, while the Appro ran SUSE LINUX Professional version Shared disk storage was handled by an nstor 4500F Series storage system. The system was populated with four IBM and four Seagate Fibre Channel drives, which were formatted as two independent RAID 5 arrays, in order to provide approximately 1TB of total storage that would be divided among the three servers. For robust performance and transparent fault-tolerance, the nstor 4500F system was set up with two RAID controllers in an active-active configuration. With a central storage system configured in this manner, a seasoned system administrator can optimize I/O across servers by assigning different primary controllers to different arrays on different systems, while at the same time eliminating the possibility that a disk controller would be a single point of failure. To complement the inherent fault tolerance provided by the active-active dual-controller configuration of our storage system, we chose to implement a basic dual switch topology for our SAN fabric. Given the number of devices being networked into our SMB SAN environment, a single 16-

7 The Out-of-Box Experience port SANbox 5200 would have been more than sufficient to support the current structure and leave plenty of room for future expansion. A singleswitch topology would, however, leave the switch as a single point of failure and violate our business constraint to provide the most robust 24x7x365 systems availability possible. Needless to say, such robustness against device failure was not deemed necessary for shared tape drives. In fact, we deliberately chose an Exabyte Mammoth2 drive with a 1Gb SAN interface in order to test the automatic speed sensing function of ports on the QLogic SANbox 5200 switch. The working assumption for our evaluation of the QLogic-based SAN was that all of this equipment would be in place and in working order prior to the arrival of the SAN HBAs and switches from QLogic. The operating systems would be installed and running on the servers. The fundamental RAID arrays on the shared storage system would be already initialized, which will take several hours with a terabyte or more of total storage capacity. Given those constraints on our working test SMB environment, a key evaluation criterion would be how quickly we could get our initial twoswitch SAN fabric up and working. Remarkably, we were able to go from boxed HBA and switch equipment to a fully-functional fault-tolerant working SAN in just 30 minutes. The Out-of-Box Experience Adding an additional switch into a fabric built on stackable switches is just as easy as configuring the first switch. 07 Opening the box containing a QLogic QLA234x HBA, system administrators will discover a card included with the driver installation CD with instructions to check the QLogic website for the latest drivers. In all likelihood, such a trip will be completely unnecessary. That s because the QLogic drivers have been included in all of the latest operating system distributions. As a result, our most taxing moments installing the QLogic HBAs came when we needed to tell the Windows 2003 servers why we were shutting them down. Both Windows Server 2003 Server and SUSE LINUX Professional recog-

8 The Out-of-Box Experience nized the new hardware and immediately installed the proper drivers. More importantly on the Linux side, the QLogic driver was recognized as a disk controller and not simply as a Fibre Channel interface. As a result, the QLogic drivers were automatically added to the initrd ram disk, which is loaded at boot time. Unfortunately, this is not the case with all Fibre Channel HBAs. Other HBAs will be recognized when the system is configured; however, they will not be automatically added into initrd, which will not be automatically rebuilt. This task, which is rather trivial to do, must be performed manually by the system administrator. While the task of manually rebuilding initrd is rather trivial, there is one rather serious problem: There is no warning that this task must be done. Worse yet, failure to carry out this task will cause the next system boot to fail if any SAN-based disk was left mounted at the time of shutdown. Without the driver loaded in initrd, Linux will not be able to see, let alone check, the file system on that drive. Once the Fibre Channel HBAs are installed on the servers, the next step is to configure the switches and create a SAN fabric. Upon opening up a box containing a QLogic SANbox 5200 switch, there is a software CD containing versions of SANbox Manager for Windows, Linux, and Solaris. Also included in the box is a folded sheet of paper entitled the "Quick Start Guide." 08 For anyone who has previously installed a SAN switch, an exceptionally terse "Quick Start Guide" will likely cause some serious consternation. Starting with Step 5 (Apply Power to the Switch), moving to Step 6 (Install SANbox Manager), and then followed by Step 7 (Run the Configuration Wizard-after first connecting the switch to the Ethernet), we found the brevity of documentation disconcerting. There was not a word about configuring a serial port, launching Telnet, or running a complex menu-driven configuration program. Not without some trepidation, we proceeded to follow the instructions in the "Quick Start Guide." Not surprisingly, the installation of SANbox manager on Windows Server 2003 Server was a trivial and near instantaneous task. Quite surprisingly, the installation of SANbox Manager on SUSE LINUX was an equally instantaneous and trivial task. Marking the time, we launched SANbox Manager on our SUSE LINUX server.

The Out-of-Box Experience We began the process of configuring our first SANbox 5200 switch in our test fabric via the SANbox Manager wizard at 2:01pm.

9 The Out-of-Box Experience We began the process of configuring our first SANbox 5200 switch in our test fabric via the SANbox Manager wizard at 2:01pm. 09 Immediately upon launching the wizard associated with configuring a new switch, it was clear that QLogic has concentrated on solving a lot of the annoying problems that plague systems administrators at SMB sites. For smaller sites, where the installation of new network devices is not a frequent occurrence, having to begin the set-up process via telnet over a serial connection is cumbersome at best, and for some, a daunting hurdle. Thanks to some installation wizardry, there is no need for serial connections or the specialized cables that such connections can require. An administrator simply plugs an Ethernet patch cord into the SANbox 5200 switch and allows the network device discovery process to go to work. The SANbox Manager wizard begins by asking for a temporary IP address that it will assign the new switch during the configuration process. Once that address is entered, the wizard then requests that the administrator recycle power on the target switch. The wizard then quickly discovers the powercycled switch and puts it on the LAN using the given temporary address. With LAN communications established, what follows is a simple series of configuration options for the switch:

The Out-of-Box Experience 1. A SAN domain ID number 2. A SAN symbolic name 3. A permanent means for LAN address configuration 4. The date and time for the switch 5.

10 The Out-of-Box Experience 1. A SAN domain ID number 2. A SAN symbolic name 3. A permanent means for LAN address configuration 4. The date and time for the switch 5. A new password for the administrator That's it! Within ten minutes of starting the process, we had configured and were ready to commit our first fabric drive. Within ten minutes of starting the wizard to configure a SAN switch, we were ready to commit the switch profile. 10 Normally, adding a second switch to a SAN fabric is a more complicated task than entering the first. An administrator must first decide how many ports on each switch will be dedicated to the creation of an inter-switch link. Since each port on a switch is independently capable of delivering data at 2Gb per second to or from a device, two questions must be answered: 1. How many ports on each switch might be communicating with ports on the other switch at the same time? 2. How fast are the devices connected to each port?

11 SAN Lifecycle Management Alternatively, a good rule of thumb is to dedicate four ports on each 16- port switch to provide a bandwidth of 8Gb per second for inter-switch traffic. Once the decision is made concerning the number of ports to divert to inter-switch traffic rather than to the task of connecting devices, an administrator must then configure each of the ports on both switches to handle their appropriate job. Most switches will automatically sense that a port is connected to a port on another switch and not a device. In such cases, the switch will automatically configure such a port as an E-Type rather than an F-Type. Nonetheless, there is still more to the task that must be done manually. In order for the switch to load balance across a number of independent E-Type connections, the corresponding ports on each switch must be logically linked into a single trunk. On the other hand, adding an additional switch into a fabric built on QLogic s SANbox 5200 stackable switches is just as easy as configuring the first switch. Each QLogic stackable switch comes with four additional 10Gb-per-second load-balanced ISL ports and a special cable to interconnect ISL ports between switches. By simply interconnecting two 10-Gb ISL ports on each switch with the cables provided with each SANbox 5200 switch, our test SMB fabric had a completely configured 20Gb-per-second trunk without losing a single data port. We were then set to run the wizard that would add the second switch and complete the fabric. Just 30 minutes from starting with the installation of the QLogic HBAs, we were ready to start configuring SAN-based disks on our Windows and Linux servers. SAN Lifecycle Management One of the most critical problems for a system administrator within a SAN environment is access control of devices. 11 Getting a SAN fabric up and running is only a starting point. Far more important for the long run is the ease with which a SAN can be monitored and maintained. Once again, the host-based SANbox Manager software that is included with QLogic SANbox switches far outstretches the capabilities of switch-based web tools. In fact, for advanced device configuration within our test SMB SAN environment, SANbox Manager provid-

SAN Lifecycle Management ed critical information needed to ease configuration of our nstor 4500F storage system that was not available from switch-based tools.

12 SAN Lifecycle Management ed critical information needed to ease configuration of our nstor 4500F storage system that was not available from switch-based tools. One of the most critical problems for a system administrator within a SAN environment is access control of devices. This is especially critical when Windows servers are members of the SAN. The purpose of a SAN is to distribute logical SCSI devices to multiple systems. When the SCSI device is a tape drive and it appears on multiple systems, there is little cause for concern, as the operating systems are well adept at detecting a busy tape drive. Unfortunately, this is definitely not the case for a disk drive. The first thing Windows wants to do upon discovering a new disk drive is write a signature on the drive. Linux is better behaved, but not all that much. Without the addition of an external file system that can handle shared physical media, it is essential that logical disk units created on a storage system array be mapped in one-to-one fashion to a unique server within the SAN fabric. 12 Zoning of a SAN fabric is simplified by SANbox Manager's ability to report on end-toend devices within the topology. Such a one-to-one mapping can be configured using SANbox Manager to create soft/hard zones within the fabric based on any of the ports on any of the switches. By simply clicking on ports to create zones based on collections of ports, the system administrator can limit which HBAs can

13 SAN Lifecycle Management discover/access devices. SANbox Manager s ability to identify the devices, such as HBAs, RAID controllers, and tape drives that are connected to each port greatly simplifies the zoning process. What s more, the end-toend reporting of SANbox Manager makes it much easier to use even more powerful tools associated with SAN-attached devices. As a case in point, nstor provides a host-based tool for managing nstor storage systems dubbed StorView. Using StorView, a systems administrator can explicitly map logical disk drives partitioned from the physical array to any HBA connected to the fabric. Using the logical unit number (LUN) of a logical array and mapping it explicitly to an HBA is a highly optimal alternative to port-based zoning; however, to do this, an administrator must be able to identify a server from the WWN code number of the HBA plugged into it. 13 By clicking on the Name Server tab in the topology view, an administrator can get an end-toend listing of all devices in the SAN fabric. Such a report is not often available from switch-based SAN tools. One way to do this is to identify the switch port that is connected to the HBA with the particular WWN code. While QLogic s host-based SANbox Manager readily reports this information, many competitive switch-based tools do not report it. Additional host-based fabric management software must be purchased and installed to capture this data.

14 Conclusions Conclusions The combination of dedicated 10Gb-per-second ISL ports in the SANbox 5200 switches and SANbox Manager, a wizard-based host software package for SAN fabric management, provides a revolutionary improvement in the simplification of SAN implementation. By providing a hardware infrastructure and a software-monitoring tool that can enable an SMB site to bring up a SAN in 30 minutes, QLogic radically rationalizes the SAN as an attractive SMB storage approach. 14

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