18
Hardware Installation and User’s Guide
Hardware Specifications and Features
3.3.2
Support for Non-Hard-Disk-Drive SCSI Devices (Non-Direct-
Access Devices)
The RAID controller will pass through to the host operating system direct access to non-
direct-access SCSI devices which are connected to a SCSI bus (channel) of the RAID
controller. The RAID controller passes through all control of these devices to the host
operating system.
Types of supported non-Direct-Access SCSI devices (this does not cover specific vendors
and models):
•
SAF-TE Processors.
•
Tape Backups. Check with your vendor. Some manufacturers recommend that you do
not connect a tape backup drive directly to a RAID controller of any kind.
•
CD-ROMs.
Table 3-4. Supported SCSI Device Standards
SCSI Drive
Standard
Speed
(MB/Sec)
Bus Width
(Bits)
Maximum Cable
Length (meters)
(1)
Adapter Maximum
Devices per SCSI
Channel
Single-
Ended
LVD
SCSI-1
(2)
5
8
6
(3)
8
Fast SCSI
(2)
10
8
3
(3)
8
Fast Wide SCSI
20
16
3
(3)
16
Ultra SCSI
(2)
20
8
1.5
(3)
8
Ultra SCSI
(2)
20
8
3
N/A
4
Wide Ultra SCSI
40
16
N/A
(3)
16
Wide Ultra SCSI
40
16
1.5
N/A
8
Wide Ultra SCSI
40
16
3
N/A
4
Ultra 2 SCSI
(2, 4)
40
8
(4)
12
8
Wide Ultra 2
(4)
80
16
(4)
12
16
Ultra160 (Ultra 3)
160
16
(4)
12
16
Ultra320
320
16
(4)
12
16
Notes:
1. May be exceeded in Point-to-Point and engineered specific applications.
2. Use of the word "Narrow", preceding SCSI, Ultra SCSI, or Ultra2 SCSI (for example, Narrow
SCSI) is optional.
3. LVD was not defined in the original SCSI standards for this speed. If all devices on the bus
support LVD, then 12-meters operation is possible at this speed. However, if any device on the
bus is singled-ended only, then the entire bus switches to single-ended mode and the distances
in the single-ended column apply.
4. Single-ended is not defined for speeds beyond Ultra.
After Ultra2 all new speeds are wide only.
