Ask Dr. Bob

My company is looking for a Storage Area Network (SAN) solution. We'll probably use the SAN for general network storage and as a repository for Oracle and Microsoft Exchange Server. We've narrowed our search to three contenders: the EMC CLARiiON FC5300, the Hitachi 6846, and the Dell PowerVault 650F. Which do you prefer?

You can use a SAN to store just about every type of data, from a full-blown Oracle 11i installation to a simple data repository to an Exchange Server database. When you're deciding on a SAN solution, how much of your decision should you base on data type—in regard to capacity, performance, and availability?

Although you always want to invest in a solution that provides the best possible performance, some applications are simply more resource-intensive than others. Oracle and Exchange Server, for example, typically require a faster disk subsystem than general data storage requires. General data storage, on the other hand, might need greater storage capacity than Oracle or Exchange Server requires. You'll need to find a happy medium between performance and capacity.

The EMC CLARiiON FC5300, which uses disk drives as large as 73GB, can house as many as 30 drives; therefore, you have a raw capacity of approximately 2TB. The FC5300 offers dual controllers and mirrored 512MB cache, greatly enhancing overall read/write performance. In the event of controller failure, the FC5300 retains data written to cache in the failed controller.

The FC5300 uses dual-ported Fibre Channel Arbitrated Loop (FC-AL) drives—not SCSI—and comes with two connections per controller. You can update the FC5300's microcode without rebooting the system or losing access to data. The FC5300 has dial-home capability over the Internet or telephone lines; thus, EMC can continuously monitor and register potential problems on the FC5300. This capability also allows for remote diagnostics and problem resolution. EMC gives you a 24 X 7 warranty and a 2-hour response-time guarantee.

The Hitachi 6846 is a fairly new addition to Hitachi's data storage line. The largest drive you can use in the 6846 is 36GB. Like the FC5300, the 6846 can house 30 drives, giving you a total capacity of approximately 1TB. Hitachi has no plans to provide a larger drive capability in the 6800 series. The 6846 has a twin controller and as much as 1GB of mirrored cache. Hitachi claims that its unique caching algorithm can produce near RAID 1 performance on a RAID 5 data set. This feature, which significantly increases potential storage capacity, is particularly attractive to those of us running Oracle on RAID 1. (At Hitachi's Web site, you'll find white papers about test cases for running Oracle on RAID 5.) The 6846 uses all SCSI drives internally, but not to the detriment of overall performance.

Like the FC5300, the 6846 has twin fibre connections for each controller. Each fibre connection can run at 100MB, giving you a grand total of 400MB. (The FC5300 and the Dell SAN give you a total of 200MB.) You can update the 6846's microcode without rebooting or losing access to data, and you get dial-home capabilities over network and modem. Unfortunately, you can use these connections only for logging data, not for problem resolution. The warranty is 24 X 7 with a 4-hour response time.

EMC produces the Dell PowerVault 650F, but this solution has more in common with Hewlett-Packard's HP SureStore E Disk Array FC60 than EMC's FC5300—except that the 650F uses all fibre drives and the FC60 is still tied to SCSI. The 650F uses 36GB drives and holds as many as 10 drives per enclosure, but you can connect as many as eleven 10-disk enclosures to provide a maximum capacity of nearly 4TB. The 650F houses two controllers and as much as 512MB of mirrored cache.

The 650F uses all fibre drives, and each controller has two fibre connections, providing 100MB per controller. You can independently update the microcode on each controller without rebooting or losing access to data. The 650F offers only a network connection for logging errors, and you need to punch a hole in your firewall to grant access. The warranty is 24 X 7 with a 4-hour response time.

If you want to implement a full-blown SAN solution, the EMC FC5300 is an attractive option. However, EMC won't guarantee its product in a SAN environment unless you purchase a set of dual Brocade switches and additional software. This configuration can add as much as $70,000 to the purchase price, making the FC5300 the most expensive of your choices in a SAN environment. Regarding up-front costs, the Hitachi 6846 is the most expensive of the three products you mention, and the Dell 650F is the least expensive—by more than $15,000 dollars. (The FC5300 starts around $50,000; the 6846 around $62,000; and the 650F around $31,000.) Unlike the EMC SAN, the Hitachi and the Dell SANs will work with switches from third-party vendors.

Another important concern when judging a fibre SAN is the product's compatibility with other fibre devices. Of the three solutions, the FC5300 is the least compatible with other fibre devices. This incompatibility is apparent in the company's inability to guarantee successful operation if you use other manufacturers' switches and fibre host adapters. To no avail, I tried to implement a Spectra Logic BullFrog backup device in a serverless backup scenario on an FC5300. Apparently, EMC guarantees that only ADIC drives will work on its SAN. Conversely, both Hitachi and Dell provide a list of compatible switches, host adapters, and tape devices. (The BullFrog device worked fine on both systems.) I prefer a more open architecture than EMC's, but only you can decide which solution will work best in your environment.

How do I disable my CD-ROM drive's autoplay feature in NT 4.0?

You need to edit the registry. Using your favorite registry editor (i.e., regedt32 or regedit), navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom\Autorun subkey. Set this subkey's value to zero.

My Practical Peripherals Pro Class 288 PC Card modem is driving me crazy. The modem seems to be in working order, but Windows NT always gives me a Port is Busy error message. What's going on?

Ridiculous as this solution might sound, you need to boot into NT 4.0 while the Easy-Jack connector is still in the modem. After you've booted NT, simply pull out the jack and connect your phone line.

The Port is Busy message is deceiving. If, during setup, I set my ISDN line speed to a value that is too high, I get the same message. Obviously, the port isn't busy; NT simply isn't returning the proper error message.

My company recently purchased an Iomega Jaz drive. No matter what I try, I find that the tool drive is password-protected. I can't even format it. What do I do?

Despite Iomega's claims to the contrary, I believe the drive is indeed password-protected. Either that or the partition and file information is proprietary. Reboot the system, and run a low-level SCSI format command on the drive. Use Disk Administrator to set the partition, then format the drive. Note that Disk Administrator can't assign an extended partition to removable media.

I've inherited a set of strangely formatted tapes that I can't erase using NT Backup. Do you have any suggestions?

To solve your problem, you can add the /nopoll switch to NT Backup. Nopoll means exactly what you'd think: Don't poll the tape's contents. Use the /nopoll switch only to erase tapes.

I'm trying to install Microsoft Access 97 on a Windows NT machine that previously ran Access 2000. The installation completes successfully, but when I try to run Access 97, I get the error Microsoft Access can't start because there is no license for it on this machine. How can I fix this problem?

You're experiencing a common problem among users attempting to downgrade from Access 2000. Fortunately, a fairly simple solution exists for this mysterious problem, which involves a TrueType font file.

First, find the hatten.ttf file in the \%systemroot%\winnt\fonts directory (i.e., the default location). Second, rename the hatten.ttf file to, for example, hatten.sav. (You can use any unused extension.) Third, reregister Access 97: Rerun Access's Setup and use the /y switch (i.e., setup/y).

When I attempt to install Microsoft Office 2000, I get an error message that states Installer terminated prematurely. How do I fix this problem?

First, try installing Microsoft Internet Explorer (IE) 5.0 or later before you perform the regular Office setup. You'll find IE on the Office 2000 CD-ROM, or you can download it from Microsoft's Web site.

If that fix doesn't work, try renaming the odbccp32.dll, odbcint.dll, and msdasql.dll files. I tend to use the .old or .sav naming convention, but almost any unused extension will work. After you rename these files, run Setup again. If neither option solves your setup problem, try downloading the latest Microsoft Data Access Components (MDAC) from Microsoft's Web site.

End of Article