AOC-USAS-L8i Add-on Card User’s Manual
7-2
7-2 IM and IME Features
IM and IME support the following features:
• Configurations of one or two IM or IME volumes on the same SAS controller. IM
volumes have two mirrored disks; IME volumes have three to ten mirrored disks.
Two volumes can have up to 12 disks total. (Requires Integrated RAID firmware
v1.20.00 or above.)
• One or two global hot spare disks per controller, to automatically replace failed disks
in IM/IME volumes. (Support for two hot spares requires Integrated RAID firmware
v1.20.00 or above.) The hot spares are in addition to the 12-disk maximum for two
volumes per SAS controller.
• Mirrored volumes run in optimal mode or in degraded mode (if one mirrored disk
fails).
• Hot swap capability.
• Presents a single virtual drive to the OS for each IM/IME volume.
• Supports both SAS and SATA disks. The two types of disks cannot be combined in
the same volume. However, an SAS controller can support one volume with SATA
disks and a second volume with SAS disks.
• Fusion-MPT architecture.
• Easy-to-use BIOS-based configuration utility.
• Error notification: the drivers update an OS-specific event log.
• SES status LED support.
• Write journaling, which allows automatic synchronization of potentially inconsistent
data after unexpected power-down situations.
• Metadata used to store volume configuration on mirrored disks.
• Automatic background resynchronization while host I/Os continue.
• Background media verification ensures that data on IM/IME volumes is always
accessible.
7-3 IM/IME Description
The Integrated RAID solution supports one or two IM/IME volumes on each SAS
controller (or one IM/IME volume and one Integrated Striping volume). Typically, one of
these volumes is the boot volume, as shown in Figure 7-1. Boot support is available
through the firmware of the SAS controller that supports the standard Fusion-MPT
interface. The runtime mirroring of the boot disk is transparent to the BIOS, drivers, and
operating system. Host-based status software monitors the state of the mirrored disks
and reports any error conditions. Figure 7-1 shows an IM implementation with a second
disk as a mirror of the first (primary) disk.
