Dell PERC 4/SI - Manual (Page 24)

LED Operation
The LED on the drive carrier indicates the state of each drive. For internal storage enclosures, see the storage enclosure user's guide for more information
about the blink patterns.
PassThru (Legacy) SCSI Channel
The RAID controller provides the ability to use a passthru (legacy) SCSI channel. This is known as "RAID/SCSI mode." Use this option for one RAID channel for
hard drives and a legacy SCSI channel for removable devices or pre-existing hard drives. You can select this option in system setup interface. This is available
for PERC 4/Di and 4e/Di only.
Devices attached to the SCSI channel are not controlled by the RAID firmware and function as if they are attached to a regular SCSI controller.
The devices and capabilities supported under the SCSI channel are:
l Hard drives
l CD drives
l Tape drive units
l Tape drive libraries
l Support of domain validation, data CRC, double clocking, and packetization
RAID Configuration Information
Table 3 -1 lists the configuration features for the RAID controller.
Table 3-1. Features for RAID Configuration
RAID Performance Features
Table 3 -2 displays the array performance features for the RAID controller.
Table 3-2. Array Performance Features
NOTE: Unlike initialization of logical drives, background initialization does not clear data from the drives.
NOTE: The passthru SCSI channel is available only on certain platforms. See your system user's guide for more information.
Specification PERC 4/Di/Si PERC 4e/Di/Si
Number of logical drives and arrays supported Up to 40 logical drives and 32 arrays per
controller
Up to 40 logical drives and 32 arrays per
controller
Support for hard drives with capacities of more than eight
gigabytes (GB)
Yes Yes
Online RAID level migration Yes Yes
Drive roaming Yes Yes
No reboot necessary after capacity expansion Yes Yes
User-specified rebuild rate Yes Yes
Specification Description