Midrange Stuff, OS/400 Edition

iSeries tape management specialists LXI Corp. last week announced that OS/400 shops can now get the performance benefits of using IBM's 3580 LTO Ultrium tape drives without actually buying one. LXI says that the new 3580 emulation capability in its OmniServe bridge/router allows OS/400 servers to "see" non-IBM LTO tape drives as if they were full-fledged IBM drives, providing up to a 20 percent increase in data transfer speeds.

The iSeries recognizes two types of LTO drives: the 3580, manufactured by IBM, and everything else, which the iSeries recognizes as a T200 drive, says LXI product manager Tim Kormos. When the iSeries encounters one of these third-party T200 drives, it creates a generic *TAP device definition for it and treats it like a standard quarter-inch (QIC) tape drive. The server also automatically performs software compression when writing to the drive.

These two factors (the compression and the QIC format) combined reduce the native data transfer rates of LTO drives from 30 MB per second, Kormos says. When using an IBM 3580 LTO Ultrium tape drive, transfer rates are 20 percent higher than using a generic T200 connection, according to internal tests performed by LXI. With the OmniServe device providing 3580 emulation, any third-party LTO drive can achieve the full 30 MG per second (compressed 2:1) data transfer speed, Kormos says.

Irving, Texas, based LXI has been selling OmniServe for about a year. The device is an "intelligent" bridge/router that allows servers to share tape drives, disks, and other storage devices, over SCSI or Fibre Channel protocols. The OmniServe is manufactured by TD Systems, a Northborough, Massachusetts, company specializing in storage area network interoperability. Pricing for OmniServe starts at about $8,000. The 3580 emulation is an add-on feature that costs $1,500.

iSeries shops can save money with the 3580 emulation because they don't have to buy an IBM 3580 LTO Ultrium tape drive, which tends to be more expensive than LTO drives from other manufacturers, to get full LTO performance. An iSeries shop could purchase an Ultrium tape drive from StorageTek, for example, and get performance that previously only users of IBM's Ultrium tape drive could get. But it's worth nothing that StorageTek gets its Ultrium tape drives from IBM, through an OEM relationship, so IBM still gets its share.

The OmniServe was designed to consolidate numerous, disparate tape drives and simplify a company's backup procedure. Instead of having independent tape drives to back up individual servers, OmniServe allows users to back up multiple servers, running disparate operating systems, onto a single drive--or multiple drives, as the case requires. OmniServe supports a range of devices, including LTO tape drives from IBM and StorageTek; Mammoth-2 drives from Exabyte and IBM; digital linear tape (DLT) from Quantum (not supported on OS/400); and 3590 and 3590-compatible tape drives from IBM and StorageTek. The OmniServe also connects to a variety of Fibre Channel and SCSI host bus adapters and Fibre Channel fabric switches, providing older, non-Fibre Channel compatible AS/400 boxes with some storage area network capabilities.

LTO, or linear tape open, is a relatively young tape drive format that has found much support in the midrange server market. The creation of the LTO format was a joint effort between IBM, Hewlett-Packard, and Seagate Technology, to develop a licensable and open tape standard that provided good performance and, more important, wouldn't require a company to pay high prices for tape media from a company that kept the technology proprietary. Competing formats--such as DLT, which was developed by Quantum, or Advanced Intelligent Tape (AIT), which was created by Sony--may outperform LTO in some respects, but they are proprietary formats.