Dell PowerVault MD1120 - Manual (Page 17)

A REFERENCE GUIDE FOR OPTIMIZING DELL™ POWERVAULT™ MD1XXX FAMILY SAS SOLUTION VER A02
PAGE 17 6/16/2008
5. PERC 5/E and PERC 6/E Controller - Detailed Features
PERC 5/E
PERC 5/E is the RAID controller used to connect the PowerVault MD1000 storage enclosure with
PowerEdge servers. It supports 3 Gbps Serial Attached SCSI (SAS) as the storage interconnect
technology and PCI -E as the host-based interconnect technology. PERC 5/E controller supports
RAID levels 0, 1, 5, 10 and 50.
PERC 6/E
PERC 6/E is the RAID controller used to connect the PowerVault MD1xxx Family of storage
enclosures with PowerEdge servers. It supports 3 Gbps Serial Attached SCSI (SAS) as the
storage interconnect technology and PCI -E as the host-based interconnect technology. PERC 6/E
controller supports RAID levels 0, 1, 5, 6, 10, 50, and 60.
Considerations when implementing a RAID Solution
The selection of a RAID solution in any environment is governed by several aspects including
controller and capacity requirements. Each of these factors is discussed in detail in the following
sections.
Controller Features
The Server Administrator is the recommended application for configuring and managing the
PowerVault MD1xxx Family. Apart from the Server Administrator software, the common BIOS
configuration utility ( ) of PERC 5/E and PERC 6/E RAID controllers may be used to
perform pre-OS configuration and fault recovery. Some of the key features of the PERC 5/E and
PERC 6/E controller are listed here:
• Virtual Disk Initialization
PERC 5/E and PERC 6/E controllers are capable of performing initialization on the virtual
disk(s) by either writing 0’s to a portion of the physical disk (fast initialization) or to the
entire physical disk (full initialization). Full initialization guarantees that any legacy data is
cleared and all sectors are healthy.
• Background Patrol Read
Background Patrol Read is an automatically scheduled background task that scans and
resolves possible physical disk errors that may lead to physical disk failure and result in
data integrity issues. Dell recommends implementing Background Patrol Read in all the
configurations.
• Consistency Check/Background Initialization (BGI)
Consistency checks / BGI are performed by PERC 5/E and PERC 6/E controllers to verify
that all stripes in a redundant virtual disk are consistent and to automatically correct stripes
where inconsistencies are found. BGI is a consistency check that automatically runs on all
redundant arrays. Depending on workload, Dell recommends that consistency checks are
run manually on virtual disks at least once every month to ensure data integrity. Running a
consistency check is complement to running Patrol Read and both should be used.