Monday, March 24, 2008

Snap Server vs the Competition: NAS Storage Comparison

Bake-Off: Network-Attached Storage

Whenever the conversation turns to storage, SANs tend to hog the spotlight. However, there are valid technical and financial reasons for picking NAS, especially when several machines need access to the same set of data.

CRN Test Center reviewers set out to examine middle-of-the-road NAS products that support 2 Tbytes to 4 Tbytes of storage space and have a Gigabit Ethernet interface. The five products that made the cut were Adaptec Inc.'s Snap Server 520, Buffalo Technology Inc.'s TeraStation Pro II, Hewlett-Packard Co.'s ProLiant DL320s Storage Server, LaCie's Ethernet Disk, and Netgear Inc.'s ReadyNAS NV+. These capacities represent the maximum for each unit, which were not the same as the as-tested capacity.


Reviewers calculated technical rankings by looking at performance, feature set and capacity-per-dollar. Capacity-per-dollar was calculated on a standard 2-Tbyte storage system. Channel programs were also considered.

In the interest of standardizing storage types, each system was configured with a single RAID 5 array setup at the largest size possible. Each unit was connected to the same switch as the testing PC.

Two tests measured performance. First, two directories with various file types were copied from the testing PC to the NAS and back again. The 1.2-Gbyte directory contained 23 files and the 3.2-Gbyte directory had 41. Operations were timed.
Then Iozone testing software measured I/O performance on files from 32 Mbytes to 10 Gbytes. Results were plotted to see which system had the best overall performance across various file sizes.

Other considerations included environmental factors such as noise level, power draw and heat output; feature set; applications; types of connectivity; supported platforms; failover capabilities and management options.

Running the Numbers

Iozone tests both file sizes and record sizes when measuring read/write speeds. When the results were plotted, HP ProLiant DL320s Storage Server creamed the competition. It measured 815,151 KBps (796 MBps) on writing a 32-Mbyte file with 64-Kbyte records, while the next highest performer, LaCie Ethernet Disk, measured 285,787 KBps (279 MBps). Oddly enough, LaCie Ethernet Disk has less features but consistently outperformed Adaptec Snap Server 520 across all file sizes, while Buffalo's TeraStation Pro II and Netgear's ReadyNAS NV+ had virtually identical results. Buffalo and Netgear win points for consistency—their speed remained essentially the same regardless of file size. After 128 Mbytes,
however, LaCie's read/write speeds dropped close to Adaptec's speeds, which remained slightly better than Buffalo and Netgear. The HP results remained consistently high, but had a sharp decline after 1 Gbyte, bringing it closer to the rest of the competition in order of magnitude.

HP ProLiant DL320s Storage Server

HP's ProLiant DL320s Storage Server snatched first place on the combined strength of its channel program, I/O performance and features. Priced at $6,666, it was the second most expensive offering in this comparison, but it's worth it for environments where performance matters.

The ProLiant DL320s test system was a 2U enclosure with 12 250-Gbyte SATA drives, providing up to 3 Tbytes of storage. SAS drives are also supported. The ProLiant DL320s Storage Server comes in several size configurations, including 1.7 Tbytes, 3 Tbytes, 3.6 Tbytes, 6 Tbytes and 9 Tbytes. It can easily support 25 to 200 users.

Since the DL320s does not come in units lower than 3 Tbytes for SATA disks, the price-per-capacity is presented at 3 Tbytes for this system only.

The ProLiant DL320s Storage Server ships with the Microsoft Windows Storage Server 2003 RC2 operating system preinstalled and preconfigured. When powering it on, the system runs the Rapid Startup Wizard, which collects
network configuration information. Once the wizard is complete, the system is available over CIFS, Samba, NHS, HTTP, FTP, WebDAV, AppleTalk and NetWare file protocols. Reviewers used the Storage Manager interface to create a new 2-Tbyte RAID 5 volume spanning all 12 drives.

For all practical purposes, this is a regular Windows server—but one that has been optimized to be a storage device. The registry has been tweaked to deliver files faster and data duplication features have been added. It comes with a dual-core Intel Xeon 3070 2.67GHz processor, 2 Gbytes of memory (expandable up to 4 Gbytes), a DVD drive and dual hot-plug power supplies. VARs can install security applications and third-party storage applications to complement HP's Storage Manager tool. It can also function as a print server.

To simulate drive failure, reviewers pulled the drive out of the chassis at random. The system logged the problem and immediately rebuilt the array so data was not lost.

HP performed better on large, multifile directories. It took 2:19 minutes to read and 2:11 minutes to write 1.2 Gbytes of data and 7:59 minutes to read and 6:11 minutes to write about 3 Gbytes. It was consistently faster on the writes than on the reads.

Netgear ReadyNAS NAV+

Netgear ReadyNAS NAV+ nabbed second place on the strength of its channel program and its deep feature set. The ReadyNAS matched more expensive competitors feature for feature at a significant cost-savings.

It is a desktop solution that packs a large wallop into a small case. The price-per-capacity, $1,599 for 2 Tbytes, is solidly in the midpoint compared with the other four products.

The ReadyNAS NV+ supports RAID 0, 1 and 5 as well as its own X-RAID (Expandable) configuration. The device has four hot-swappable drive slots and an integrated backup manager that allows for one-button backup to an external USB hard drive or remote server. It is expandable via three USB 2.0 ports. The ReadyNAS NV+ can support up to 20 concurrent users and can also be configured as a DHCP server and a print server. It has an informational LCD panel concealed
behind a mirror on the front that is only visible when lit.

The unit comes preconfigured in X-RAID to expand storage capacity when drives are changed. Reviewers manually reset the system to create the RAID 5 volume. Although the administrator console is browser-based, the RAID configuration is done through a client application called RAIDar. This application is easy to use, but it's an extra program that solution providers need to remember. Drive failure was simulated by pulling out a drive. When the drive was replaced, the system needed to rebuild the array, which took a little more than four hours.

The intuitive administrator console allows all kinds of ReadyNAS management, going so far as to allow recalibrating the fan and show temperature readings down to each disk.

On performance, the ReadyNAS took 53 seconds to read and 1:11 minutes to write 1.2 Gbytes of data and 16:48 minutes to read and 10:25 minutes to 3.2 Gbytes of data. At 69 dB, noise levels were comparable to the other units
tested, but seemed much louder as it was a desktop unit. It drew only 58 watts of power.

ReadyNAS is built with the future in mind. As higher-storage capacity disk drives hit the market, it will be able to accommodate them, all the way to the theoretical four 16-Tbyte hard drives that will max out the system's storage capacity at 64 Tbytes

Adaptec Snap Server 520

Adaptec Snap Server 520
, despite its robust feature set, lost out to Netgear and ended up in third place. At a list price of
$6,445 for a 2-Tbyte configuration, the Snap Server has the highest price-per-capcity value compared with its competitors. Netgear had the advantage of having a lower price-per-capacity while matching many of Snap Server's features. However, the Snap Server 520 stands apart from its competition in one regard: While the other vendors submitted storage products, Adaptec submitted a complete solution.

With two Gigabit Ethernet ports, a print server, backup and antivirus software, the 1U enclosure comes with four 750-Gbyte hot-swappable SATA drives. Its two-line LCD displays status information, system ID and IP address. The Snap Server is a system with an eye toward future growth. The box can have its internal memory upgraded up to 4 Gbytes. Seven expansion bays make a maximum capacity of 66 Tbytes possible.

Mounting the rack on rails proved to be a frustrating exercise. Otherwise, installation was simple. The extremely well-laid out, browser-based administration interface allowed reviewers to see the status of, and configure, almost everything imaginable. It is clearly one of the unit's high points.

Connecting to the shares was as easy as typing the path within a command line or, preferably, mapping a drive letter to it from a remote machine.

At nearly twice the size of the LaCie, the extra surface area allowed the Snap Server to operate at almost room temperature, 69 degrees, in the front of the case, and only 10 degrees warmer in the back. This was much cooler than the other contenders. On the flip side, at 78 dB, it was a noisy system and drew about the same amount of power as the HP ProLiant DL320s, peaking at 130 watts during startup before dropping down to the 90s.

Read and write tests showed that the Snap Server's speed improves somewhat with larger files. It took the longest to read and write 1.2 Gbytes of data at 2:11 minutes to read and 2:09 minutes to write. It took 8:37 minutes to read and
15:26 minutes to write 3.2 Gbytes.

LaCie Ethernet Disk

Even though it lacks many of its competitors' features, the LaCie Ethernet Disk was a favorite during testing. The lack of features such as individual disk status information, support for the NFS protocol and a front LCD panel hurt the Ethernet Disk in this particular comparison and helped land it in fourth place, but its performance and price-per-capacity stand out.

Despite being the cheapest unit on price-per-capacity, at $949 for 2 Tbytes, the LaCie Ethernet Disk turned in better performance than two of its competitors, Netgear and Buffalo. LaCie Ethernet Disk has four hard disk drive slots and can
support as many as 25 users simultaneously. The test system had 4 Tbytes of storage and is priced at $1,999.

LaCie ships with a Microsoft Windows XP Embedded operating system preinstalled. The OS allows Ethernet Disk to easily join a Windows domain using Active Directory. It also supports Samba, AFP, FTP, HTTP and Bonjour file-sharing protocols. There are four high-speed USB 2.0 ports for backup onto external hard drives, or for capacity expansion. There are also PS2 mouse/keyboard ports and a VGA monitor connector, none of which LaCie recommends using.

The 1U rack-mountable unit came with little rubber feet (or as one reviewer called them, "booties") to cover the protruding ends, allowing it to be safely used as a stand-alone device. Optional rails for rack mounting are also available. Installation and configuration was, by far, the easiest of all the units tested. Reviewers mounted the system in a rack, connected the power and network cables and turned it on. After boot, there is already a share called Public created and ready to use. The browser-based, tabbed administration application is intuitive, but sparse on features.

Although generating more heat than the others, the LaCie was quiet and drew considerably less power than the other products. The power draw peaked at 66 watts during startup and stabilized at 63 watts.

While Ethernet Disk lacks features, it performs well. It took 1:11 minutes to read and 1:30 minutes to write 1.2 Gbytes of data, and 13:02 minutes to read and 6:41 minutes to write 3.2 Gbytes of data.

Buffalo TeraStation Pro II

Despite having the second lowest price-per-capacity, at $1,200 for 2 Tbytes, the TeraStation Pro II from Buffalo placed fifth because it lacked the robust feature set and performance capabilities of its competitors.

Rackmount and desktop versions are available in 1-Tbyte, 2-Tbyte and 4-Tbyte capacities. A desktop is also available in 3 Tbytes. The TeraStation test system was installed with four 1-Tbyte 7,200-rpm hard drives to get a 4-Tbyte storage capacity. The 4-Tbyte TeraStation Pro II is available for $2,200.

Drives can be configured in RAID 0, 1, 5, 10 and JBOD. External drives or additional units can be linked via its two USB 2.0 ports. A LCD display shows the drive and the system's status, network configuration and any error messages. Once the TeraStation Pro II is hooked up on the network, it immediately obtains an IP address from the DHCP server and displays it on the LCD screen. Once it has an IP address, the TeraNavigator software, available under Windows and Apple's OS X, detects it. The NAS Navigator is the client utility and displays system information and configuration settings. The TeraStation Pro II supports Samba and FTP for file sharing and can be synced with a time server. The system can support Active Directory integration and DFS. The fault-tolerant RAID mode allows hot-swapping SATA drives. It also has a built-in FTP server.

The system is quiet, despite a large fan, even more so as a desktop unit and is quieter as a desktop unit than as a rackmount. The heat-release design keeps the unit very cool, even after eight hours of intensive file copy operations. It drew more power than the sleeker LaCie system or the comparable Netgear box, drawing a peak of 94 watts during startup, stabilizing at 86 watts after several hours.

The TeraStation Pro II was the slowest performer, taking 25 minutes to read and 31 minutes to write 2 Gbytes of data. Other data sizes were not tested as a result

Wednesday, March 12, 2008

Adaptec's little SAN that can

Snap Server 720i, an entry-level iSCSI SAN, packs big features in a small format

Adaptec Snap Server 720i was selected for an InfoWorld Technology of the Year award.

Many different combinations of drives, controllers, and software are available in storage arrays for small and midsize businesses, but one example that you should not miss is the Snap Server 720i that Adaptec trotted out last week

With the 720i, Adaptec proposes an affordable yet scalable iSCSI SAN module that doesn't skimp on performance and is easy to manage. From my early test-drive, I can attest that the 720i delivers on those promises, despite a minor hiccup or two.

This compact 1U box comes with four SATA drives, a single power supply, and three Gigabit Ethernet cards to connect to an iSCSI SAN and to your management console. A choice of 250GB or 500GB drives puts total capacity at 1TB or 2TB, but if you need more you can daisy-chain as many as eight

Adaptec SANbloc S50 expansion modules
, 2U enclosures loaded with as many as 12 SAS (serial attached SCSI) or SATA drives.

You don't find many storage solutions in the SMB space that can expand so easily to 100 drives, making the 720i an interesting proposition for small companies that expect their capacity needs to grow significantly.

The two evaluation units I received from Adaptec had a nominal 2TB capacity, but using RAID 5 with a hot spare drive leaves little more than 900GB available on each one.

SANbloc expansion modules
will be needed if that's not enough for you.

The Adaptec controller inside the 720i supports just about any RAID level, including dual parity protection, which is a common-sense choice for large SATA drives. Still, having only four drives in the array limits your choice to either
RAID 5 or mirroring, neither of which protects against a second drive failure while recovering from the first one. However remote that possibility may be, adding an expansion module to the 720i is a surefire remedy, because the addition of more drives gives you more choices in RAID levels.

Another option is to get a second 720i and mirror volumes across the two, so you can easily switch to the second array if the first one goes south -- more on this later.

Easy Storage Manager

Setting up my two 720i was, yes indeed, a snap. I connected the management port to my data subnet and the other two GigE ports on the back of the unit to my SAN. Considering the 720i has only one power supply, it's good that the onboard management software can also monitor a UPS.

If you have used other products from adaptec, Storage Manager will look like an old friend. Regardless, it won't take long to get acquainted with its GUI, from which you can centralize the monitoring of all of your arrays. In addition to typical management tasks such as setting up the network configuration and creating LUNs (logical unit numbers), Storage Manager allows you to provision storage without even touching your Windows machines.

After installing an agent on each of my application servers, I was able to create and assign new volumes remotely from the management console. Behind the scenes, the provisioning agent took care of formatting the volume, assigning a drive letter and preparing the Microsoft iSCSI initiator for the connection -- this last step is very helpful because it
avoids having to jump between consoles.

During my testing I ran into a couple of network hiccups. For example, restarting after a sudden power off, the array
didn't respond to Storage Manager or to a ping. Nevertheless, the 720i's powerful CLI, which you can access via telnet or serial port, came to the rescue.

The Adaptec CLI's comprehensive online help -- which will even guide you word by word through a command -- puts most
similar tools to shame. I never needed to keep a reference manual close by to type a command, and neither will you.

Magical mirroring

The 720i feature that takes the cake is the built-in remote mirroring. Naturally, mirroring requires two arrays but brings ironclad protection to critical volumes by automatically creating remote mirrors of selected volumes on the second unit.

Remote mirroring is also very easy and quick to implement; in fact, creating a mirror is faster than explaining how it works. Here is how: From Storage Manager I clicked on one of my application servers, chose the volume to protect, and
then clicked the appropriate entry from the pop-up menu. The wizard proposed to create a new volume of the same size on the second array, and I clicked Next and Apply to confirm. My mirror volume was set.

To mimic a real-life scenario, before testing the fail-over, I added more files to the source volume, then increased its size by 5GB. Peeking at the second array, I noticed that Storage Manager had quietly increased the size of the mirror as
well -- so far, so good.

To simulate a failure, I simply pulled the power cord from the 720i. In the time it took me to return to the console, Storage Manager was showing that the array was down. From my application server, I opened the "lost" volume in Windows Explorer and all of my files, including the last batch, were still there. The automatic fail-over was successful; the system had automatically switched my server to the mirror volume.

I don't know if the power-off hiccups I experienced were caused by the array or by some glitch on my network, and frankly it doesn't matter much because sudden power loss is an unlikely event in most installations. What counts more is
that the Adaptec Snap Server 720i combines great scalability, reassuring high-availability features, and excellent management tools, all at a very affordable price and with a three-year warranty on hardware. Few arrays in its class can even come close to that.

Cost-Effectively Expand Storage Capacity Without Straining IT Resources

Every company is faced with a rapidly growing amount of business data this that must be continuously available to all the employees who need it. The latest regulations require business data to be retained and accessible for years, even after it is no longer critical for daily business. It all adds up to data that can easily overwhelm available storage resources.

The Challenge: Easy, Cost-Effective Capacity Scaling

62% of small businesses and 56% of medium-sized businesses still rely on direct attached storage using internal disks, according to IDC. Direct attached storage offers the virtues of low cost, high reliability, and easy management, but it is difficult to scale. Adding capacity requires opening the server and adding individual disks. Eventually, there is no more room to add disks. Yet, many IT managers are reluctant to move to a networked storage solution, fearing that it will require extra cost, increased time to implement and complexity that will strain already-tight IT resources.

The Solution: Direct Attached SAS RAID with Adaptec Serial Attached SCSI RAID 4805SAS/4800SAS Controllers and SANbloc S50 JBOD

The Adaptec Serial Attached SCSI RAID 4805SAS/4800SAS controllers and SANblocS50 JBOD put the performance, reliability and investment protection of the Adaptec Unified Serial™ Architecture together in one complete, convenient storage expansion solution. It allows easy external expansion of DAS without moving to networked storage, and managing all the attached capacity with the same, familiar Adaptec Storage Manager interface that manages DAS. Each SANbloc S50 JBOD holds up to 12 disks. Daisy-chaining provides massive scalability. Using Snap Server by Adaptec, connect up to eight JBOD units to the Adaptec 4805SAS/4800SAS RAID controller. You have the flexibility to install Serial ATA (SATA) drives for low cost and high capacity, Serial Attached SCSI (SAS) drives for high performance, or mix them in the same system to achieve the right price/performance balance. Upgrading or reallocating storage later is as easy as swapping out disks.

How it Works

Simply install the Adaptec 4805SAS (PCIe) or 4800SAS (PCI-X) card into your server. Then, connect the S50 JBOD and populate it with SATA and/or SAS drives.As your storage needs grow, attach additional JBODs by daisy chaining them to each other. Each SANbloc S50 can accommodate up to 9TB of SATA disks or 3.6TB of SAS disks.

Easy-to-Use Storage Management

This solution uses the same, familiar Adaptec Storage Manager (ASM) that many IT managers already know. The intuitive ASM tool centralizes management of all Adaptec RAID cards in the company. Remotely configure, monitor, and manage RAID through secure, encrypted communication. Pop-up tips and online help simplify RAID array creation and management.

Unmatched Data Protection

Adaptec delivers a proven RAID core hardened over years of use in demanding environments. The Adaptec 4805SAS/4800SAS controller offers the most advanced RAID feature set with RAID 0, 1, 5, 10, 50, RAID Level Migration, and Online Capacity Expansion without downtime. Then we take it farther with the Adaptec Advanced Data Protection Suite, standard with Adaptec 4805SAS/4800SAS controllers. Enjoy the dual drive failure protection of RAID 6 and 60, the ability to mirror across an odd number of disks with RAID 1E, and the ability to use a hot spare while using all the drives for data of RAID 5EE. Copyback Hot Spare allows you to designate a drive location as a hot spare. After drive replacement, the controller migrates back to the original configuration. Optional Snapshot Backup creates point-in-time copies of an array for better data backup.

True Reliability and Fault Tolerance

Hot-swappable drives and redundant, hotswappable power and cooling are standard with the SANbloc S50. Plus, each disk drive has its own dedicated 3Gb SAS channel and point-to-point connection. Unlike traditional SCSI where a failed drive can bring down the entire bus, the SANbloc S50 isolates the failure to the affected drive.

Fast Throughput

This solution is ideal for data- and transaction-intensive applications. The dual SAS host connections of the SANbloc S50 transfer terabytes of data at up to 1200MB/s each, for an aggregate bandwidth of 2400MB/s. The Adaptec 4805SAS/4800SAS transfers data at rates up to 3Gb/s, then about 300MB/s, per port.