Important Notice: Our web hosting provider recently started charging us for additional visits, which was unexpected. In response, we're seeking donations. Depending on the situation, we may explore different monetization options for our Community and Expert Contributors. It's crucial to provide more returns for their expertise and offer more Expert Validated Answers or AI Validated Answers. Learn more about our hosting issue here.

How do you create a RAID array using IDE/Ultra DMA disk drives and why does an IDE/Ultra DMA RAID controller use a SCSI interface?

April 26, 2017array controller create disk DMA drives IDE raid SCSI Ultra

0

Posted

How do you create a RAID array using IDE/Ultra DMA disk drives and why does an IDE/Ultra DMA RAID controller use a SCSI interface?

1 Answer

0

Posted

Until recently, all RAID systems used SCSI disks. However, it is possible to use just about any type of disk in a RAID array. IDE disks with DMA can now run at up to 100 MB/sec, but because they cannot be daisy-chained in the same way as SCSI and Fibre-channel drives, they require a special RAID controller. Economy RAID systems such as the E800 series offer good to very high performance whilst using inexpensive drives. However, they do need one channel per disk, so are limited to a maximum of 8-12 disks in one RAID array. The RAID controller uses an Ultra-3 SCSI host channel because IDE has a very limited cable length and lower bandwidth. This means that although IDE disks are used, the RAID appears to the host as a normal SCSI device.