Networked Storage by jharris

Networked Storage Also Inside :

Take a Wide-angle View of IT…4

RAID Levels Explained…7

A supplement to

B y Dan O chiva

Hooking Up

Building Blocks of Networked Storage

surveillance, for Seagate Technology. That market is robust. In the third quarter of 2007, networked-storage sales grew 5.1 percent from a year ago to $4.4 billion, according to the IDC Worldwide Quarterly Disk Storage Systems Tracker. That marks 19 consecutive quarters of year-over-year growth, according to the research organization.

DAS for basic storage

Ne t worked Storage

CalDigit HDElement

We’ve all experienced how hard-drive storage costs just keep plummeting: Each year, you get more for less. Computing power (remember Moore’s Law?) and bandwidth continue to be better deals too. Putting that all together in networked storage, the next step beyond simple direct-attached storage (DAS), just makes sense. “Anytime access to content is best delivered via a networked-storage infrastructure that utilizes high-capacity and high-performance disk arrays in a NAS or SAN architecture,” says Mark Wojtasiak, global marketing manager, video

DAS setups, where a storage device is directly attached to a host system, remain the most common method of storing data; the drives are attached internally to a workstation or function as part of a server. Any workstations networked in such a system must first access the server in order to connect to the storage device. This is probably the simplest storage to set up—and it’s comparatively inexpensive. But such a setup faces its own set of potential problems. For example, if the server is down or experiencing problems, users might not be able to store or access data. In addition to storing and retrieving files, such servers usually host other software apps, such as

email and databases. That means network bottlenecks and slowdowns in data availability may occur as server bandwidth is consumed by those apps. But if you don’t have to share information over long distances or across an enterprise, DAS is a good place to start. It offers easy management and administration— especially in the case of an attached server, because that device’s software can be used to manage files. However, managing becomes more complex if you attempt to add more servers, because storage for each server must be administered separately. Examples of DAS products come from Fantom Drives, G-Technology, and Nexsan. Fantom G-Force MegaDisk NAS ( fantomdrives.com) offers eSATA and USB 2.0 connectivity as well as multiple RAID options and capacities up to 2TB. G-Technology (g-technology.com) taps 3Gbps eSATA connectivity to deliver the entry-level-priced G-Speed eS, which supports multistream SD and uncompressed HD video editing. Storage capacities range to 4TB,

with configurations available as RAID 0, RAID 1, RAID 5, or JBOD. The Nexsan SATABeast Xi (nexsan. com), built for the Xserve and Mac Pro markets, offers both Fibre Channel and iSCSI connectivity. Compactness is one of the product’s selling points; it offers up to 42TB of storage in only 4RU of rack space.

Apple Xsan 2

NAS: Bring in the network While network-attached storage (NAS) might, at first, seem similar to a DAS setup with a traditional file server equipped with directattached storage, it’s very different on the software side. NAS devices, which use a minimal or stripped-down operating system often based on Linux, specialize in data storage, data access, and managing that data. They usually offer control via a web interface instead of a standard computer’s keyboard/mouse. NAS devices offer relatively simple and cost-effective ways to achieve fast data access for multiple clients at the file level. Like traditional file servers, NAS devices include the components used in a typical PC—such as a CPU, RAM, and a motherboard. Similar to a server, it follows a client/server design, with clients usually accessing NAS over an Ethernet connection. You might hear terms such as “NAS box” or “NAS head.” That refers to the fact that such devices act as an interface

between the NAS and network clients. On a network, any NAS units appear as single nodes that display an IP address. NAS systems usually allow you to add additional storage as desired to increase total capacity. Client workstations will always connect to the NAS head, however, rather than to the individual storage devices. NAS devices simplify network traffic when used with other servers that might be handling email, for example, because the NAS will be dedicated to serving files to workstations. Therefore, you’ll sometimes hear a NAS product referred to as a file-storage device, because it uses file-based protocols such as NFS (network file system) or SMB/CIFS (Microsoft uses server message block/common Internet file system for Windows networking). Examples of NAS products come from Norco and Archion. The Norco DS-520G Network Storage Appliance (norcotek.com)

includes five hot-swappable SATA II drive bays and three eSATA and four USB 2.0 ports. Its eight individual SATA channels enable capacity of up to 8TB. The DS-520G supports OS software including Windows Home Server, Linux, and OpenBSD—or other open-source NAS software such as Openfiler, FreeNAS, and Samba. Archion designed its Synergy HD (archion.com) to work within an Avid Unity environment, as well as Apple Final Cut Pro and other editing software. It employs SATA II drives, 2GBps Fibre Channel (FC) connectivity, as well as Ethernet and RS-232 ports for control and communication. Archion certifies Synergy HD with Avid Unity 3.x through 5.x. While Synergy HD offers up to 8TB of storage, the newer Synergy HDU tops out at 12TB and includes two 2GBps ports.

SAN: Networked storage on steroids While they’re not solely the domain of large corporations, storage-area networks (SAN) are the most flexible and complex method of networking storage devices together. SANs originally only used Fibre Channel (FC) technology for connections because it offers low-latency, high-bandwidth data transfer among various types of devices. SANs are generally speedier than NAS configuration because they access data at the block level—specific areas where information is physically stored on the disk. A NAS approaches information on the higher, logical level of a file, familiar to users who look for data by file and folder names. Block-level transfers in a SAN are generally faster than file-level transfers in a NAS because there is no file system or network overhead. But speed has its price. Workstations connected to a Fibre Channel SAN require expensive FC host bus adapters (HBAs) and FC switches, while fiber-optic cabling is still more expensive than Ethernet-style Cat-5 or Cat-6 cable used in many NAS systems.

Storage devices on a SAN, along with workstation clients, are connected with each other and to a server, which offers access to the network via a switch. Added flexibility comes from the fact that more than one server can be incorporated into a SAN, allowing remote users in a building or around the world to access the system. While a storage system will be tied to a specific server in a NAS setup, SANs allow access to any combination of servers and storage. Although small computer system interface (SCSI) is the most typical protocol used in storage networks for communications between drive arrays and servers, it’s not the actual physical way everything is hooked up. Instead of difficult-to-manage, short-range SCSI cables, SANs commonly connect over fiber-optic cable or topquality copper wiring.

Nexsan SATABeast Xi

Ne t worked Storage

Take a Wide-angle View of your Organization’s IT Infrastructure

You’ll also run into an alphabet of “mapping layers” with a SAN. A few of the standards that are used to control SCSI signals include the original Fibre Channel and more recent iterations that employ Internet connection technology including iFCP (Fibre Channel over Internet networks); and iSCSI (SCSI over TCP/IP, or Internet protocol). Topologies, meanwhile, describe how FC ports can interface: Point-to-Point (limited to two devices connected together); Arbitrated Loop (all devices are in a loop or ring; if one device fails, say an HBA, the loop breaks); and Switched Fabric (provides optimal interconnections, because all devices are connected to FC switches). In February, Apple (apple.com) made some major SAN moves when it does introduced Xsan 2 software while announcing that its Xserve RAID product—the hardware heart of its original SAN, introduced in 2004—was being discontinued. While it was innovative at its introduction, Xserve RAID remained a limited offering—from its use of parallel ATA drives (other manufacturers were moving towards SATA) to staying with RAID 5, which can survive one drive failure (many others moved to RAID 6, which Continued on page 6

B y J eff E lterman It is useful to take stock of your organization’s existing data-network and storage capabilities before you consider investing in costly storage equipment. Document your organization’s workflow with a narrative accompanied by a workflow chart and detailed key of the elements in your organization’s IT infrastructure. For example, if animation is part of your production pipeline, write a narrative documenting sequential workflow in the animation process. A simple animation workflow narrative could state: “Animation production begins with animators animating 2D characters, CG artists modeling 3D characters and props, and designers creating backgrounds and props digitally. Digital animators then composite all of these elements together into a final shot—including all the animation, CG, and designs. After rendering, the final shots are ready to be cut into the edit system for final output to tape.” Do the same for your organization’s video-editing process—from ingest to editing on NLEs to nearline storage to archive to tape. Once you have the narrative for each production process your organization uses, draw a schematic diagram illustrating the number of computers

in each department for each task in the narrative. You should also draw in the network Ethernet connectivity between the workstations and servers, as well as the storage type and capacity each server has access to—for example, local storage in the server, SAN, NAS, etc. Make a key for the schematic to drill down to greater detail to document the number of computers in each department of your organization—OS kernel, software applications used in the production process, NLEs, the capacity and type of disks, SCSI, Fibre Channel, SAS, SATA, etc. Identify the bottlenecks in your organization’s workflow that need to be addressed. For example, you may identify a workflow bottleneck such as video editors being unable to start keep up with project demand because there is insufficient free disk capacity to continue working. Your editors may complain that they need more disk capacity on the storage their NLEs read and write to. However, you will want to look for the most cost-effective solution— which may not necessarily be purchasing additional disk capacity for your video editors, but may instead be investing in nearline storage to move data from expensive disks to relatively inexpensive Continued on page 6

Moving on to metadata It makes sense to look among the DAS, NAS, and SAN systems when you’re putting together a system for straight-ahead editing. But if you’re working with lots of disparate sources and projects while recording out to video, the Web, and other media, you’ll want to integrate some sort of metadata capability with your storage sooner or later. After all, metadata—more commonly referred to as data about data—is designed to help track diverse media over time. Buying into a media-asset-management system, however, can be daunting when you’re faced with the wide variety of products now coming to market, many with steep opt-in prices. One product line with an interesting mix of capabilities and a relatively low price point comes from Focus Enhancements (focusinfo.com). Its entry-level PX media servers and ProxSys media-asset-management systems were introduced to the U.S. market at NAB 2007. Focus is better known as a manufacturer of a line of popular portable DTE hard disk recorders for camcorders. But its PX-1 Archive Management Server, a Linux-based NAS device, offers a good solution for small groups of editors who would appreciate fast search and retrieval of HD and SD video content—as well as its ability to handle graphic, audio, and data formats such as PowerPoint and Word documents.

“As users move to HD, the need for storage is growing exponentially in video post,” says Robert Caldeira, senior product manager for Focus Enhancements. “But if you want to do quick searches to find the material you are looking for, you’re not going to want to dedicate all the bandwidth you’d need to transfer those huge files around your network.” The server includes capture suite and media import software to generate low-res proxies, highly configurable metadata capability, and the ability to seamlessly import video content from Focus digital disk recorders and/or Panasonic P2 Material eXchange Format while preserving all native metadata, such as the six-folder structure of P2 data. Users can access the server from local workstations via its web-browser-like GUI, or with any standard web browser from anywhere you can get an Internet connection. At the 2008 NAB Show, Focus will expand the ProxSys hardware and software asset management product line, adding features including support for Apple FCP XML interchange format and native QuickTime support. “There’s a continuing trend of AV and IT converging,” Caldeira says. “We’ve created a turnkey device that gives you a Google-like ability to search for your video and a YouTube ease in playing it back.” —D.O.

Continued from page 4

can handle up to two drives failing). Dropping Xserve RAID allows Apple to forego competing in the aggressively competitive storage hardware market by partnering with RAID storage developer Promise Technology (www.promise.com), which has won a place on Apple’s website. At MacWorld 2008, Promise announced that its VTrak E-Class RAID subsystems have been qualified with Xsan 2, Apple’s high-performance SAN file system for Mac G-Technology G-Speed eS OS X, and Final Cut Studio. Each RAID subsystem initiator for OS X. The delivers 26 streams of 8-bit uncompressed SD video and software, available as a supports capacities up to 24TB per configuration. free download, allows With its new Xsan 2 software, Apple worked to users to create their own simplify the arcane setup of an FC SAN. SAN Setup iSCSI/IP-based SAN. Assistant, part of Xsan 2, starts up when the software SNS recently announced sees that a Fibre Channel card is installed; the software that its globalSAN product handles tricky configurations, such as setting up Open line would now ship with Directory permissions. 750GB drives. The turnkey Long a provider of Mac-oriented audio/video globalSAN products now network storage systems (the company’s gear works offer 50 percent more with PCs too), Studio Network Solutions (SNS, storage—up to 12TB in the studionetworksolutions.com) drew kudos for developing X-16 model. and making available its innovative globalSAN iSCSI

disks until the data is archived to tape. Further, the method of archiving projects, for example archiving to Digi Beta tape, may be cost-effective for SD productions; whereas, it may be more cost-effective to archive to LTO for HD production because Digi Beta tape alone cannot archive the multiple formats comprising HD productions. Addressing the bottleneck at the most cost-effective part of the workflow process is often not apparent without the wideangle view. Of course, bottlenecks may occur at any point in the production process, and I have found that my customers appreciate the perspective the wide-angle view brings to the decision making process for important IT purchases. DigitalMix provides consultation, sales, and service for major video post and broadcast facilities. You may contact Jeff Elterman at DigitalMix at (516) 922-2221.

RAID : Hardware versus software

Ne t worked Storage

All RAID cards aren’t created equal.

“Hardware RAID versus software RAID is a very important consideration,” says Jon Schilling, manager of sales at CalDigit. Schilling says that some RAID cards don’t actually implement their RAID levels in hardware, but emulate it via software, which ends up using CPU cycles that an editing program might need. (Today’s trend towards multicore processor CPUs may offer some relief.) But other problems with using a software RAID could be more detrimental, according to Schilling. While a non-hardware RAID card could still create a RAID 5 array, for example, it would offer little or no protection if the system crashed. Hardware-based RAID cards are more expensive than softwarebased cards, but that’s because they also include independent cache memory, an embedded CPU to handle the RAID calculations, and usually a GUI to allow system monitoring. Such hardware RAID cards also allow users to add more drives

to a larger array without having to wipe the data first. The CalDigit RAID Card (caldigit.com), introduced at MacWorld 2008, works at RAID 5 (as well as RAID 0, RAID 1, RAID 6, and JBOD). Pricing at a modest $549, the card handles up to 16TB at a claimed 247MBps throughput speed. The company’s new HDElement, debuting at the 2008 NAB Show, is a four-drive external bay that works with the CalDigit RAID Card. Available in 1TB, 2TB, 3TB, and 4TB versions, HDElement is said to deliver up to 250MBps throughput. Up to three arrays will run off a single RAID card; CalDigit claims that when the arrays are striped together, the system can offer 20GBps bandwidth. “If you want to edit in true uncompressed HD, you can do it for less than $1,000 [with this system],” Schilling says. “That’s just not something you could do five years ago—especially with hardware RAID and the benefits that come with that.” —D.O.

RAID levels explained You’ll hear “RAID” everywhere when you deal with storage for editing; it’s the general term for techniques used to securely divide and replicate data among multiple hard disk drives. If you use a smaller storage array with only two drives, you’ll typically deal with RAID 0 or RAID 1, while putting together larger systems with three drives or more will usually mean you work with RAID levels 5 or 6. Here’s a short list of the most commonly used RAID levels in video post. For more information, visit acnc.com/raid.html or en.wikipedia.org/wiki/RAID.

RAID 0 RAID, originally described as Redundant Arrays of Inexpensive Disks, doesn’t really turn up in RAID 0, because data isn’t as protected via redundancy or fault tolerance. However, it’s the fastest and cheapest such setup for editing, requiring a minimum of two drives. Remember to back up regularly.

RAID 1 RAID 1, sometimes described as mirroring, is an easy-toimplement, entry-level, redundant system. But because one drive is used to store a duplicate of the data, it’s slower than RAID 0 and it wastes much more drive space.

RAID 3

RAID 3 stripes data over multiple drives, with one drive dedicated for holding parity information. (Parity uses extra generated bits for error checking.) It’s similar to RAID 5 in that it improves performance and fault tolerance over RAID 0 and RAID 1, but it’s not as popular as RAID 5, because that one dedicated parity drive slows disk writes down. Meanwhile, data can be lost if that one drive goes bad, but with RAID 5, any one disk can die and no data disappears.

RAID 5 While it’s considered inefficient when dealing with large file transfers (that’s not usually a big problem during video editing), RAID 5 is one of the most popular RAID levels when working with three or more drives. If a drive fails, it will requires replacement, but the array is not destroyed by any single drive failure.

RAID 6 RAID 6 evolved out of RAID 5, and it is becoming more popular in larger systems that use higher-capacity drives. It doubles the amount of parity for additional fault tolerance. While it requires a minimum of four drives to implement, it’s possible for more than one drive to fail simultaneously, and the RAID array will still operate. —D.O.

A look ahead at Digital Content Producer’s Resource Reports for 2008

May 2008: Stock Footage July 2008: Education and Training October 2008: Top Facilities

Use what the Professionals use G-Tech is the defacto standard in post production facilites worldwide

From DV to HD and beyond, weâ&#x20AC;&#x2122;ve got your storage covered Performance. Style. Reliability. www.g-technology.com