Adaptec GDTSETUP Bedienungsanleitung PDF herunterladen (Seite 90)

disks, which are connected with different SCSI channels of the ICP Controller, both write-

accesses are performed simultaneously (this method is often called Disk Duplexing). During

a read-access of the host computer the data will be read from the Logical Drive whose hard

disk has the fastest access to the data requested.

If a hard disk should fail (for instance due to a mechanical defect), all data is still available

on the other Logical Drive. In this event, the controller gives an acoustical alarm.

Steps 5 and 6

are the same as in example 1.

&([DPSOH,QVWDOOLQJD5$,''LVN$UUD\

This example is applicable to ICP Controllers with the RAIDYNE firmware.

The controller we use is the ICP Controller with three SCSI channels.

&0HFKDQLFDO6WUXFWXUH(OHFWULFDO&RQQHFWLRQV

Whether to install the SCSI hard disks into the computer case or into a separate disk sub-

system enclosure strongly depends on your individual hardware equipment, therefore we

shall not discuss it here. However, it is very important that the hard disks and the ICP Con-

troller are cooled with a sufficient and constant air flow and that the power supply of the

system is strong enough for the desired configuration. You may use a separate power sup-

ply for each hard disk in order to avoid power failure (what sense does a redundant Host

Drive make if all hard disks forming the Host Drive are operated with one single power sup-

ply and this power supply fails ?). All participants of a SCSI-bus must have a different SCSI-

ID. In addition, both ends of the SCSI-cable must be equipped with SCSI-bus terminator

resistors. The SCSI-bus termination is crucial, since it is highly probable that a wrongly

terminated SCSI-bus will cause malfunctions of the connected devices and data transfer

problems. The ICP Controller for this example has three independent SCSI channels: A, B,

C. In our example, two SCSI hard disks are connected to channel A (DR1, DR2), one to

channel B (DR3) and two to channel C (DR4, DR5). Our connection scheme is:

1 2 ... 85 86 87 88 89 90 91 92 93 94 95 ... 217 218

Keine Kommentare

Adaptec GDTSETUP Bedienungsanleitung Seite 90