What’s the deal with SCSI?

SCSI is pronounced “skuzzy” and stands for Small Computer System Interface. It is a way of interfacing the disk drives and the motherboard together. SCSI is not usually used in desktop environments for several reasons. First, the hardware for SCSI is generally more expensive than its IDE counterpart hardware. Second, IDE is much simpler. Third, IDE is universally accepted whereas certain drivers are required for certain SCSI adapters. So why use SCSI?

• Up to 8 Daisy-Chained Disk Drives
• RAID Support
• (Under debate) Speed
• Quality/Reliability/Data Integrity

In SCSI, you can have up to 8 disk drives daisy chained onto one cable, whereas you can have only two in an IDE setup. For servers, this is an extremely convenient feature, as many servers must deal with a large amount of data. However, the main drawback is that SCSI hardware, including hard drives, are often much more expensive than IDE drives of a similar capacity.

Also, in SCSI, you have RAID support. RAID is a technology that allows for features such as disk mirroring, stripping, and other reliability/back types of deals. The scope of this tutorial is to describe how to build a server, not to explain RAID. More information about RAID can be found at http://www.acnc.com/04_01_00.html .

Supposedly, SCSI is much faster than IDE. Although I’ve seen this to be the case, newer high-end IDE drives seem to be resisting this trend. Finally, SCSI has more reliability and data integrity features built into the hardware such that less data can be corrupted or lost on the way between the motherboard and the SCSI controller.

What about Serial ATA?

Serial ATA is an emerging IDE standard that may spell the doom of the SCSI standard. Basically, serial ATA is ATA (the standard for IDE) that moves data one bit at a time, rather than one byte at a time. It has been engineered for speed and for RAID application. By 2005, the majority of IDE hard drives sold may be Serial ATA (according to some projections). Currently, however, SATA support is limited and SCSI has a deeper and wider knowledge base.

Considerations While Building

Also, remember to consider cooling, as believe it or not, the temperature of a CPU can truly affect performance, even at the server level. While my own server is no testament to what I prescribe here, I will say that the IDE cables should be confidently tucked away and any non-used power cables should be wrapped with some quality cable wrap. Make sure that you install fans and that one is intaking, and the other is blowing air out. If possible, use rounded IDE cables.

Make sure you make it easy for hard drives to be added/removed, as this is the most common operation while operating a server. Make sure expansion cards do not make it difficult for the hard drives to be removed from bays.

If you have any extra hard drives lying around, by all means, use them! Take your fastest (RPM) hard drive and set it to Primary Master, for IDE, or highest priority, for SCSI. Next, setup all other available hard drives. The more disk space, the better.

Router Security

If you have a router, make sure that you set it such that no ports are enabled on the IP of the server.