By Lisa Coleman
This year, vendors are expected to make significant strides in merging network-attached storage (NAS) and storage area network (SAN) environments, according to a recent report on network storage by the Yankee Group, a market research firm in Boston.
Vendors will expand NAS features to ease interoperability with SANs, provide content delivery management, and improve management tools. Meanwhile, next-generation NAS systems, being developed by start-ups aiming for higher-performing systems than what are currently available, will integrate global distributed file systems and provide dedicated data management capabilities, according to the report.
"I think this is the year that the SAN versus NAS debate goes away," says Jamie Gruener, senior analyst at the Yankee Group, who adds that end users will be able to use both technologies to get the best of both architectures.
The network storage market (including NAS and SAN) is expected to grow from $9.4 billion in 2001 to $24.2 billion in 2005, according to the Yankee Group's predictions. In turn, NAS will jump from about $2 billion in 2001 to $8.6 billion in 2005. However, predictions for 2002 show NAS increasing only slightly to an estimated $2.46 billion (see figure).
"When you take the ease-of-use associated with NAS and add it to a SAN, life gets a lot easier. It also accelerates the overall network storage market, so we're bullish. But I don't predict an overly aggressive growth path for 2002; that will come in 2003 and 2004," says Gruener.
NAS vendors will also expand the use of NAS connected to back-end disk arrays, deliver the ability to handle file and block semantics, and feature distributed global file systems as part of content delivery over WANs.
NAS + SAN
Large vendors such as EMC and Network Appliance are already bridging the gap between NAS and SAN. EMC's Celerra NAS device attaches to its Symmetrix arrays and uses those arrays for storing files. In February, EMC announced the latest version of its NAS headthe Celerra Data Mover 510which scales to 52TB and supports up to 224 network connections (see sidebar, "EMC enhances Celerra NAS," p. 13). Celerra is a NAS head that connects to back-end storage; EMC's Clariion IP4700 is an integrated NAS head and storage.
"Separating the NAS head from the storage gives you better scalability," says Paul Ross, director of network storage marketing for EMC. "The tradeoff is that it costs more." He says that an integrated NAS devicewith the NAS head and storage in the same boxoffers better price/performance. "The problem is that when you scale outside of what the box can hold, you have to buy a new box."
Last October, Compaq announced its NAS-SAN bridge, the StorageWorks NAS Executor E7000, which connects a NAS head to Compaq's disk arrays. Compaq dubbed the entire system "Universal Network Storage," because it has one network storage pool serving both blocks and files, with the E7000 providing file access to the SAN. The E7000 is traditional NAS-type storage, providing multi-protocol file support and also storage virtualization through pooling and snapshots. This functionality is complemented at the SAN level with Data Resource Manager and Enterprise Volume Manager for snapshots at the controller level.
This month, Compaq announced that it will expand its NAS-SAN fusion to include non-Compaq SAN connections to its NAS head (see sidebar, "Compaq expands NAS, eyes NAS-SAN convergence," p. 14).
IBM is also attaching its NAS 300G gateway product to other vendors' SANs. So far, IBM has tested the 300G with Hitachi Data Systems' Freedom Storage Lightning 9900 arrays and plans to extend interoperability to Hitachi's Thunder 9200. Acting as an IP gateway to a SAN, the 300G allows clients and servers on the IP network to access files directly from their SAN.
By year-end, Storage Computer plans to introduce a new product that will converge its CyberBorg direct-attached/SAN system with NAS functionality. The new system will also have iSCSI connectivity for block-level management.
Auspex Systems is converging NAS and SAN in its NSc3000 controller, which began shipping this month. The NSc3000 is essentially a NAS system that sits between the network and a switch. It plugs into the switch and communicates with the SAN to provide file services.
The 5U controller works with most leading SAN storage subsystems. The unit also leverages the virtual storage capabilities of Auspex's Xtreme Virtual Partitions to stripe LUNs from multiple controllers into a single logical volume, which increases throughput by providing more SAN paths to a given file system.
Vendors are also extending the ability of NAS devices to understand file and block semantics. For example, Network Appliance has been shipping its block-oriented SnapManager device for Microsoft Exchange since last September. In addition, Procom Technology's Duet software enables both file- and block-level data access in the same storage system. The software is an option for Procom's Netforce 3000 NAS filers, which were certified by Microsoft in January to work with Windows 2000 and NT 4.0.
A number of start-ups are poised to enter the NAS-SAN convergence market this year (see sidebar, "Pirus converges NAS and SAN," p. 12).
More advanced storage management tools specifically tailored for NAS will appear this year, according to the Yankee Group report. The tools will focus on four areas: content delivery over WANs, distributed global file sharing, storage resource management (SRM), and data management.
For example, Network Appliance last month introduced DataFabric Manager 2.0, a GUI-based tool for centralized management of geographically dispersed storage systems. According to Yankee's Gruener, DataFabric Manager combines many of the functions found in SRM and in content delivery tools. Version 2.0 offers an improved access control mechanism that enables secure sharing of a common Web-based management interface among many network and storage administrators. It also features a centralized console to manage the configuration and software upgrades of NetCaches.
The DataFabric Manager is one stage of a distributed global file system, which will allow users to share data without creating multiple copies. A distributed global file system is also on EMC's road map.
Several start-ups are also working on distributed file systems. For example, in December, Sistina Software released its Global File System 5.0, a clustered file system that allows multiple servers on a SAN to have concurrent read-and-write access to a shared data pool. "It essentially has the ability to take a file system, which might have been on one device, and extend it to multiple nodes," Gruener explains. This can be beneficial for companies with several locations worldwide that have users who need to access the same files. Companies can store one file in one location and securely access it from any location.
Content delivery over WANs is a goal that Storage Computer is working toward as well. Its CyberNAS product is a multi-interface NAS system capable of Gigabit Ethernet and direct OC-48c Packet-over-SONET optical connectivity to MANs and WANs.
"Clustering NAS over a WAN provides the business continuance elements of mirroring and data replication," says Todd Viegut, Storage Computer's vice president of marketing. It also offers an efficient way to manage data in a NAS environment by offering geographically dispersed clusters, according to Viegut.
Next-generation NAS system vendors such as BlueArc are focusing on building higher-performing NAS systems, content delivery, and dedicated data management capabilities, says Gruener. Today, content delivery and storage tend to be fairly separate approaches, but Gruener predicts that in the future end users will want to control and manage data from where it residesall the way across WANs.
Pirus converges NAS and SAN
By Dave Simpson
A number of start-ups plan to challenge market leaders such as Compaq, EMC, and Network Appliance with systems that merge the functionality of network-attached storage (NAS) and storage area network (SAN) architectures. Among the first to market, Pirus Networks last month began shipments of the PSX-1000 Storage Utility Switch, a router that enables resource consolidation and centralized storage management.
The first implementation of the PSX-1000 includes ServFlex File Services and Secure Virtual Storage Domain (SVSD) provisioning services. The file-serving device currently supports a back-end SAN via file protocols. In the fall, Pirus will introduce support for Fibre Channel and iSCSI block access via virtualized block storage.
"With the NAS services, you don't need [traditional] NAS heads, and you can use your existing back-end SAN storage," says Steve Duplessie, senior analyst with the Enterprise Storage Group. "The PSX-1000 allows you to manage disparate networks from a single platform."
Worcester Polytechnic Institute (WPI) is using the PSX-1000 to consolidate multiple standalone file servers, increase availability and, in the future, replicate data between buildings across its campus, according to Bob Brown, director of computing at WPI.
The crossbar switch supports multiple file protocols (CIFS and NFS) and network protocols (Gigabit Ethernet, Fibre Channel, iSCSI and, in the future, InfiniBand). The SVSD feature enables grouping of resources into logical domains in which capacity and services can be managed by application or department instead of by hardware platform.
An entry-level configuration with four file servers is priced at $85,000. This fall, Pirus will offer add-on services such as volume management and virtualization, point-in-time copy, replication, and remote mirroring.
EMC enhances Celerra NAS
By Lisa Coleman
EMC's latest Celerra network-attached storage (NAS) device, the Data Mover 510, has twice the capacity and performance of its predecessor, as well as enhanced software features for backup, automation, migration, and Windows management.
Introduced in February, the 510 is a NAS head attached to EMC's Symmetrix array. The architecture is based on 866MHz Intel PIII processors. The data movers act as a cluster of up to 14 dedicated file servers within Celerra and scale to 52TB.
EMC also enhanced its Celerra HighRoad software, which enables multi-path file sharing and delivery over a storage area network (SAN)-based link, typically Fibre Channel. For example, when a host requests a file, HighRoad finds the file via the LAN and returns the metadata and access information to the host via the LAN. The host then accesses the data via the SAN. If the file is small enough, HighRoad returns the file to the host (along with the metadata) via the LAN.
HighRoad now provides local file system replication through EMC's TimeFinder software, fail-safe networking to protect against IP network failures, and virtual LAN support.
EMC also touts HighRoad as an alternative to the Direct Access File System (DAFS) protocol, which provides a new method for high-performance and cluster applications to access file storage. Network Appliance spearheads the DAFS Collaborative, which includes more than 80 member companies.
"A lot of our customers have SANs and NAS," explains Paul Ross, EMC's director of network storage marketing. "And HighRoad enables them to integrate NAS and SAN while leveraging their existing infrastructure, without having to change any of the underlying applications."
Celerra also features native support for Windows 2000 management and security features such as Active Directory, Lightweight Directory Access Protocol (LDAP), Kerberos authentication, and Microsoft Management Console (MMC) tools.
EMC is also using NDMP for its EMC Data Manager (EDM). NDMP backup is available for NFS, CIFS, and multi-protocol environments. Qualified software includes CommVault Galaxy, Legato Networker, Veritas NetBackup, and Atempo TimeNavigator.
Finally, Celerra Concurrent Copy Backup (CCB) consolidates NAS and tape backup. CCB takes existing NDMP backup solutions and accelerates them to speeds up to 300GB per hour, claims EMC. While the data is online, a dedicated data mover running special software streams online files to a local tape library for LAN-free and serverless backup.
Compaq expands NAS, eyes NAS-SAN convergence
By Lisa Coleman
This month, Compaq extended its StorageWorks network-attached storage (NAS) family into the entry-level space and expanded NAS-SAN capabilities in a new midrange device. Compaq also announced plans to connect its E7000 NAS heads to non-Compaq storage area network (SAN) environments. In addition, the company is working on increasing NAS performance via TCP/IP offload engines.
Compaq will challenge Snap Appliances at the low end with its StorageWorks S1000 NAS device. The 1U S1000 is available in 320GB or 640GB capacities priced at $3,799 and $5,449, respectively, and can handle heterogeneous files and access. It also features snapshot and RAID support.
Compaq is also introducing the StorageWorks NAS B3000, a NAS head that connects into StorageWorks MSA 1000 SANs via Fibre Channel. The B3000, which uses the same NAS head as the E7000its high-end counterpartis a midrange device targeting users who do not have an enterprise-level SAN. It uses two-to-four processor NAS heads and scales to over 27TB. Performance scales to 130MBps CIFS throughput.
The B3000 has dual-power supplies and fans, redundant host bus adapter support, switch support, and fail-over. Prices start at $44,000.
Within the next 90 days, Compaq plans to offer connectivity from its E7000 to non-Compaq SANs. Currently, it is working with other vendors to develop support agreements.
Finally, Compaq announced it will incorporate the iSCSI standard into its NAS products, but not until the standard is finalized.