Intel raid controller srcsas144e - Manual (Page 13)

Intel® RAID Controller SRCSAS144E Hardware Guide 4
— I/0 setting: Determines whether to read/write from cache to improve performance:
^ Cache I/O: Writes to the cache and next read checks the cache first.
^ Direct I/O: Never uses cache, all data goes from host to disk to host.
• Redundancy through:
— Configuration stored in nonvolatile RAM and on the drives (COD).
— Hot swap support.
— Optional battery backup for cache memory. Controller provides fast or trickle
charges.
SAS and SATA Features
• Provides eight independent phys, each supporting 3.0 Gbps and 1.5 Gbps SAS and
SATA data transfers.
• Scalable interface that supports up to 15 SATA devices, 40 logical devices, or 32 SAS
devices via expanders.
• Transfers data using SCSI information units.
• Supports SSP to enable communication with other SAS devices.
• Supports SMP to communicate topology management information.
• Supports single PHY or wide ports consisting of 2, 3, or 4 PHY within a single quad
port.
• Allows addressing of multiple SATA targets through an expander if using SATA 2.0-
compliant hard disk drives.
• Allows multiple initiators to address a single target (in a fail-over configuration)
through an expander.
Online Capacity Expansion and RAID Level Migration Rules
• Migration must occur to the same or larger capacity configuration.
• Migration cannot occur if there is more than one virtual disk in a logical array.
• Migration and OCE cannot be done on Spanned Arrays (RAID 10, 50).
• Migrations supported are: RAID 1 to RAID 0, RAID 5 to RAID 0.
• With OCE, migrations supported are RAID 0 to RAID 1, RAID 0 to RAID 5, RAID 1
to RAID 5.