Hardware Installation and User’s Guide
19
Hardware Specifications and Features
3.4
RAID Array Drive Roaming
Array Roaming allows the user the ability to move a complete RAID array from one
computer system to another computer system and preserve the RAID configuration
information and user data on that RAID array. ††Compatible RAID controllers must
control the RAID subsystems of the two computer systems (see list of compatible
controllers in this section). The transferred RAID array may be brought online while the
target server continues to run if the hard disk drives and disk enclosure support hot plug
capabilities; however, not all operating systems support this feature. The hard disk drives
are not required to have the same SCSI ID in the target system that they did in the original
system that they are removed from. The RAID array drive that is being roamed must not
be of type Private. This includes all non-private host, array, and logical drives.
Note:
For a migrated RAID array to be recognized by the new host operating system, the host
system may need to be rebooted.
Warning:
The GDT8500RZ controller is compatible with controllers of the same product
family if those controllers have the same or a higher firmware version. Migration to
newer controller models of the same IO technology with the same or higher
firmware versions is also usually supported. However, downgrade to older
firmware versions may cause problems and is therefore NOT recommended.
Note:
Compatibility refers only to how data and RAID configuration information are written to
the hard disks. Compatible adapters have the same data file format.
3.5
Optional Features
There are no optional features for this product.
3.6
RAID Controller Drive Limitations (Host, Array,
Logical, and Physical)
The following are limitations assuming the following:
•
U160 or U320 speed depending on the SCSI controller on the motherboard
•
Dual channel SCSI controller
•
Cabling that meets U160 or U320 specifications depending on the SCSI controller
Physical drives
are limited by the number of SCSI channels being controlled by the
RAID controller. The firmware/software supports a maximum of
15
hard disk drives per
channel
(or 14 if one SCSI ID is being occupied by an intelligent enclosure processor).
The maximum number of
array drives
is limited to 35 by the RAID firmware. The actual
maximum limit of the GDT8500RZ RAID controller is
15
, see
Table 3-5
. The firmware
supports channel spanning where an array can consist of physical drives that are attached
to either one or to both channels of the RAID controller. An array drive requires a
minimum of two hard disk drives (or logical drives). Therefore the maximum array
