Keeping data within reach
- By Andreas Uiterwijk
- Dec 05, 1999
In the Information Age, government agencies must find ways to handle data generated, shared and demanded at ever-increasing rates.
And it's not just handling the volume of data that poses a problem. Today's information technology managers need to store all that data securely and determine how often and how quick-ly users need to access it.
Storage options include online, offline and near-line solutions on media including tape, hard disks and CD-ROMs. In many cases, the best storage solution is a combination of these options. To pick the solution best for your agency's needs, consider the following questions:
* Do users need instant access to data on a network? If so, an online storage solution is necessary.
The most powerful online solution is a Redundant Array of Independent Disks (RAID) device attached directly to the servers or as an additional storage device connected to the network. RAID solutions offer immediate access across the network to stored data, but this type of architecture likely will cost you more money per megabyte. Another downside: Once a RAID device is full, you need to add disks to the system or put an additional device on the network. That's decidedly more expensive than simply inserting a new data cartridge or storing the old data offline.
* What if users don't need instant access to data? Tape libraries are a good option, especially if cost is a factor in your decision.
Network tape libraries often are referred to as near-line storage. Data is accessible, but not as quickly as with RAID units. When a user requests stored data, a robotic arm locates and retrieves the appropriate tape from the library and inserts it into the drive. The drive works its way through the tape until it finds the requested data and sends it to the server. The process can take 30 seconds to five minutes, depending on where the data is located on the tape.
Such delays can be inconvenient for some users, but a trade-off lies in the ease of adding more storage space. Once a library is full, tapes can be taken offline, archived and replaced with blank tapes. This is a faster and less expensive way to increase data storage than adding RAID devices to the network. Tapes also can be easily moved to other storage locations for safety.
In this first look at network storage, the FCW Test Center tried out several tape storage devices ranging from single-server to departmental storage solutions. Our purpose is not to provide a comprehensive survey of available products. Rather, we intend to delineate the range of options available to users. In selecting products to look at, we chose three vendors who are well known in federal markets and who are representative of the industry.
We will look at RAID storage devices in an upcoming issue.
Sony TSL-SA300C AIT autoloader
Sony Corp.'s TSL-SA300C Advanced Intelligent Tape (AIT) autoloader impressed us with its ease of use and overall durability and expandability. The TSL-SA300C is small compared with the other tape libraries we looked at, measuring just 4 inches high by 8 inches wide by 11.5 inches deep.
Sony's AIT proprietary tape architecture packs a lot of storage capacity into small tape cartridges. Each cartridge holds 35G of uncompressed data, but if you employ compression, up to 70G of data can be placed on each tape. That means a total of 280G can be stored on the unit's four tapes, about equal to the storage capacity of nearly 200,000 floppy disks. Smaller 25G tapes also are available. As many as seven tape units can be strung together for additional network storage.
Setting up the TSL-SA300C was a breeze. We simply popped in a SCSI-2 Fast/Wide single-ended card into our Hewlett-Packard Co. server, connected the cable to the card from the 300C and added a SCSI terminating block to the autoloader.
Next, we installed the four AIT tapes into the caddy that ships with the autoloader and inserted the tape holder into the 300C. The 300C takes about 57 seconds to load and initialize all the tapes and just five seconds to eject the tape caddy if the tapes are in standby position. However, it can take as much as a minute to replace a tape if it's being used in the drive. The caddy lines up the four tapes with one on top of the other and end to end.
The 300C's manual shows removing the tapes as an easy process, but we had a little difficulty. Also, every time the drive needs to be cleaned, cartridges for the 300C have to be manually inserted, a tedious prospect.
The front of the 300C includes a small LCD panel that lets IT managers navigate through the autoloader settings. Although the LCD panel is small, it wasn't too hard to use. Unfortunately, there were no management or warning settings that we could see from this panel.
Finally, we installed the software that came with the unit. Sony ships Computer Associates Inc.'s ARCserveIT Version 6.61 Workgroup Edition with the TSL-SA300C. Because ARCserveIT is a first-rate program, we employed that product rather than installing Veritas Software Corp.'s Backup Exec, as we did with the other units we tested.
Performance of the TLSA-300C is rated at 3 megabytes/sec of uncompressed data and 6 megabytes/sec of compressed data. For our testing, we backed up our server completely loaded with data. We used the uncompressed native mode and backed up 19,322M of data. This backup procedure took two hours and six minutes with an average throughput of 248 megabytes/min.
To restore the files, we did a complete restore of the server. We were a little surprised to find that the process to return the data to the server took one-third longer than the initial process of backing up the unit. Specifically, the reverse process took three hours, 12 minutes to complete.
The only real downside to the 300C is its lack of management capabilities. IT managers will have a hard time trying to find out whether the hardware or the tapes are going bad. The bottom line: The 300C is best suited for smaller workgroups that employ only one or two local servers.
Exabyte's 230D DLT tape library
Exabyte Corp.'s 230D DLT tape library is more of an industrial-strength tape library. The standalone unit we reviewed sits 21 inches high, is 19 inches wide and 29 inches deep, and weighs 172 pounds. The library also is available in a rack-mountable version.
Setting up the Exabyte library took longer than the Sony unit, but the plug-and-play capabilities made overall setup painless, taking less than an hour from start to finish. First we had to install the tape caddies into the library unit. Next, we installed the additional drive that shipped with the unit. Then we prepared the tapes with the bar code labels and installed them into the unit.
Like the Sony, the Exabyte solution works with a number of software backup packages. (And, for those people using older backup software, the 230D does perform some emulation.)
The 230D with a DLT7000 drive is rated at 10 megabytes/sec uncompressed and double that if compressing the information. (The unit is also available with less expensive DLT4000 drives for IT mangers who want to protect older storage investments.)
What this unit offers over smaller tape units is more near-line storage. The 230D holds six tape caddies of five tapes each, and two additional slots are located above each drive for cleaning cartridges or additional storage cartridges. The storage capacity also is quite impressive, holding 600G of uncompressed data or 1.2 terabytes of compressed data.
The 230D has a number of setup options: You can get the 230D with single-ended or differential SCSI interfaces, and multiple SCSI channels are included in the library. This makes sharing the library between disparate networks a snap.
We did encounter some difficulties during setup when we accidentally left the unit in local mode. When in local mode, the unit only allows the IT manager to control it through the front LCD panel. The 230D looked like it was online but would not answer SCSI commands from the server or library software. The reset button on the library did not get us out of our predicament.
We used Exabyte's technical support to work through our problem to bring the 230D online. The technical support was superb, and the technician stayed online with us until the problem was resolved. We easily worked our way down through the control panel settings and solved our small dilemma.
We used Veritas' (formerly Seagate Software Inc.'s) Backup Exec to handle the backup jobs we assigned to the server. We backed up the entire server using both drives in the 230D in native mode. Full backup took an hour and 39 minutes for 19,110M. Each drive connected over a single SCSI channel moved an average of 117M of data per minute.
The 230D's expandability and high capacity makes it well suited for larger networks. We also found the unit's management tools to be easy to use and well up to the task.
ATL's LANvault 200
ATL Products Inc.'s LANvault 200 library packs a lot of storage capacity and versatility into a small box. And it takes a different approach to tape backup than the other solutions we tested. ATL's unique twist is to back up locally but manage stored data from the Internet.
A government agency can send the tape unit to a remote location, have the user plug in the unit and connect it directly to the network. From there, the unit can be remotely set up and administered from agency headquarters.
The LANvault 200 is a two-piece tape backup solution. The tape drive housing includes a single DLT7000 tape drive and eight tape storage slots that leaves the unit with one tape each for a seven-day data backup rotation and a single slot for a tape-cleaning cartridge.
Cleaning cycles can be administered remotely across the Internet. (For price-conscious agencies or agencies that have DLT4000 tapes, a unit that runs DLT4000 tapes is also available from ATL.) The tape drive unit is then connected to a control unit - a computer running Microsoft Corp.'s Windows NT 4.0 with 64M of memory, keyboard, mouse and monitor connections. However, these peripheral connections are not needed to run the unit.
Setup was no problem. We simply plugged in the cables between the library and the control unit and hooked the control unit's Ethernet connection to the network. We placed the bar code labels on the DLT7000 tapes, slid the tapes into the caddy and slipped the caddy into the front of the tape drive.
The front of the unit locks electronically to keep unauthorized users from tampering with the drive. To gain access, a small LCD panel and four small control buttons let you navigate through menu options. The one drawback is that the person plugging the unit into the remote site location will need to be a little technically savvy and possibly need phone support from headquarters. We would have liked to see color-coded or labeled cable connections to make setup even easier. Overall, however, plugging the unit in proved to be simple. To complete setup, the administrator then runs the CD-ROM that ships with the library from a remote workstation. This can be done in-house or across the Internet.
Once the administrator runs the CD-ROM, two options come up on the screen. One option allows the software to locate the LANvault on the network, and the other option installs the management and backup software.
LANvault ships with Backup Exec or ARCserveIT. LANvault can be managed through a user's Internet browser, and the unit can be set up with static or Dynamic Host Configuration Protocol options for IP address allocation.
We used DHCP, and the unit had no trouble recognizing the network and configuring the proper IP address and gateway protocols.
Management of the control unit and library was exceptional. An administrator can program the unit to send e-mail notifications that provide information on the health of the unit. Network settings and user settings also can be administered remotely through the browser.
Using Backup Exec, the backup from our server was done from the server over the network to the tape library. The other tape libraries were connected directly to our test server. We backed up the entire server in native mode.
Combined time for the full backup was three hours, 37 minutes for 19,250M. The backup was run from the server over the network to the tape library for an average throughput of 86 mega-bytes/min.
LANvault is an outstanding backup solution for remote workgroup sites or workgroups within larger office buildings. The remote management for this small unit makes it a nice addition to any agency moving toward a more managed environment.
TSL-SA300C AIT autoloader
Price and Availability: Available on the open market for $4,000.
Remarks: This small and lightweight unit is easy to set up, and its low price offers strong value. On the downside, the unit offers no network management tools and no bar code reader.
230D DLT tape library
Price and Availability: The Exabyte 230D DLT library, with two DLT 7000 drives and 30 cartridges, is available in a tower configuration and rack-mount option. Approximate GSA cost is $24,000.
Remarks: The 230D offers a generous storage capacity and is highly expandable. The unit's library management tools and its rack-mount option make the 230D a good choice for enterprise sites. We would, however, like to see stronger remote network management.
ATL Products Inc.
Price and Availability: Available on the GSA schedule through DLT Solutions Inc. for $13,808. For more information, call (888) 472-4358.
Remarks: The strongest value among the units we examined, the LANVault 200 is small, light and easy to set up. The LANVault 200 also offers excellent network management. The only drawbacks we found were slightly slow backup speeds and a relatively high price.