Backup Technology Brings New Choices

Tape has remained a popular backup solution because of its capacity, portability and low cost, but its far from perfect: Slow backup and restore performance, media failure, and periodic cleaning requirements leave many IT managers wanting.

Looking forward, organizations pursuing more efficient and reliable backup strategies should compare alternative solutions, such as removable disks and online backup, against the next generation of tape technologies.

Disk-based systems such as virtual tape libraries augment traditional tape backup, but they arent a wholesale replacement for tape. Removable disks, however, mimic the tape backup process and combine the performance of D2D (disk to disk) backup with the versatility of removable media.

ProStors RDX (removable disk extendable) devices—rebranded by Dell as the PowerVault RD1000 and resold by Tandberg Data under the QuikStor name—feature a removable 2.5-inch hard drive encased in a durable cartridge that ProStor claims can survive a 3-foot drop.

The 40GB, 80GB and 120GB drives available with Dells PowerVault RD1000 are capable of 30MB-per-second transfer rates over a SATA (Serial ATA) connection and 25MB per second over USB.

ProStor recently announced the arrival of a 160GB drive. Tapes currently support much larger native capacity—as much as 400GB—but removable disks offer instant random access, drag-and-drop functionality, and forward and backward compatibility. Removable disks also do not require cleaning.

Another option is Iomegas Rev drive, which the company introduced in April 2004. Unlike removable disk devices—which house the drive, motor and read/write head on each piece of media—individual Rev disks consist of only a hard disk platter and motor.

Rev disks come in 35GB and 70GB sizes and support a transfer rate of up to 30MB per second. Iomegas Rev server backup packages include CAs BrightStor ARCserve backup and disaster recovery software. Like removable disks, Rev drives do not require regular head cleaning, and, with an estimated 30-year shelf life, they are suitable for long-term storage needs.

Without any tapes or disks to drop in the server room or lose in the mail, online backup is another attractive option, especially for smaller shops that dont have a lot of data. eVault, recently acquired by Sea-gate Technology, continues to offer offsite backup, archiving, CDP (continuous data protection) and regulatory compliance services. Verizon, a new entry into this space, is catering to small and midsize business customers with its Online Backup service, offering as much as 50GB of storage for $40 per month.

Optical backup schemes have yet to gain serious traction in the enterprise. Products such as Plasmons UDO (Ultra Density Optical), with an expected shelf life of 50 years, are dedicated mainly to archival duty.

IT managers should weigh all these alternatives against upcoming developments in tape technology. Sonys current AIT-5 technology supports 400GB native capacity and is backward- compatible with AIT-4, AIT-3Ex and AIT-3 media. The forthcoming AIT-6 line is expected to double native cartridge capacity to 800GB.

/zimages/5/28571.gifClick hereto read Labs review of Sonys AIT-5 tape drive.

Expanding interface support for eSATA (external SATA) and SAS (serial-attached SCSI) connections also is under discussion, according to Sony officials.

The latest LTO (Linear Tape-Open) specification, LTO4, increases raw data capacity to 800GB and adds 256-bit AES (Advanced Encryption Standard) support without a performance penalty—transfer rates for LTO4 are 240MB per second, compared with 160MB per second for LTO3. The new drives are also read and write backward-compatible with LTO3 tapes and read backward-compatible with LTO2 cartridges.

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