Memory for disk arrays
Its full RAID Controllers. These RAID controllers contain "on board" all you
need to work with highly-izvoditelnymi disk systems: BIOS, allowing regardless
of the operating system to configure and format of any RAID level; RISC
processor for fast computation of amounts of control and correction of errors "on
the fly"; cache memory to store frequently used data; to 3 - x channel
controllers, working independently, each of which supports up to 15 drives.
These RAID Controllers issued in the form of fees to be installed in PCI bus.
Conclusions: The full RAID controllers meet the high demands of performance, and
reliability and can be recommended for servers middle and upper levels.
Consideration should be given to high quality memory modules-ing used for the
cache. iii. External RAID Controllers. Despite the excellent characteristics
listed above-RAID controllers, they all have significant drawback associated
with their construction. These controllers are "domestic" in the sense that they
are managed and supply voltage through the domestic tyre PCI motherboard.
Obviously, the failures and rejections of the motherboard can lead to
misinformation grounds or loss of data in a RAID-array. This lack of so-called
free external RAID Controllers. Here, the term "external" has a double meaning:
a) Such controllers are typically placed in a separate corps (usually together
with RAID-array), which has its own independent power supply; b) are controlled
through external channel SCSI controller connected to the motherboard. In terms
of the SCSI controller, an external controller with RAID disk array lag-forth as
a SCSI drive. Even constructively external RAID controller has dimensions of 3.5
"or 5.25" drive.