Dell PowerEdge RAID Controller (PERC) 6

The PERC 6 family of Serial Attached SCSI (SAS) RAID controllers supports Dell qualified SAS devices and Serial ATA (SATA) devices. It consists of two PCI Express (PCIe)–based, 3 Gbps SAS RAID controllers: the PERC 6/E adapter supports Dell PowerVaultTM  expansion enclosures and the PERC 6/i supports internal storage for Dell PowerEdge servers and Dell PrecisionTM  workstations. Each PERC 6 controller offers a 256 MB double data rate 2 (DDR2) cache memory, with the PERC 6/E supporting upgrades to 512 MB to allow quick access to additional data and help increase performance. PERC 6 controllers also include a battery backup unit to protect data in the controller cache during a system power and/or controller failure. PERC 6 controllers support RAID levels 0, 1, 5, 6, 10, 50, and 60. Learn More About RAID

PERC 6/E offers: 3 Gb/s (Gigabit per second) half-duplex max speed for each port. 6 Gb/s full-duplex max speed. Two external x4 (“by four”) SAS connectors, each containing 4 ports for a total bandwidth per connector of 12 Gb/s. x8 PCI-Express host interface for a total bandwidth of 4 GB/s. 256MB of Error Correcting Code (ECC), transportable, battery-backed, cache for base model with an option for a card that has 512MB. LSI 1078 SAS/SATA RAID-on-Chip device

PERC 6/I offers: 3 Gb/s (Gigabit per second) half-duplex max speed for each port. 6 Gb/s full-duplex max speed Internal SAS connectors, each containing directly to a hard drive for total bandwidth of up to 24 Gb/s per controller. x8 PCI-Express host interface for a total bandwidth of 4 GB/s. 256MB of Error Correcting Code (ECC) battery-backed, cache. LSI 1078 SAS/SATA RAID-on-Chip device.

PERC 6 RAID controller provides advanced media error monitoring and repair technologies designed to prevent data loss and enable safe data retrieval.

PERC 6/E enables redundant connections to the PowerVault MD1000 and MD1120, static load balancing and performance improvement over non-redundant path systems. This redundant connection also provides failover protection in case of a disconnected cable. In order to take advantage of this feature, they simply need to connect a cable between the second port on the PERC6/E and the second port on their PowerVault expansion enclosure.

The consistency check operation helps verify the correctness of data in logical drives that use RAID levels 1, 5, 6, 10, 50, and 60

Background initialization is a consistency check that is forced when creating a logical drive, and automatically begins five minutes after the drive has been created. This operation checks for media errors on physical disks and helps ensure that striped data segments are the same on all physical drives in an array.

The SMART feature monitors the internal performance of motors, heads, and physical disk electronics to help detect predictable physical disk failures.

PERC 6 controllers can automatically detect and rebuild failed physical disks when a new drive is placed in the slot where the failed drive resided or when an applicable hot spare is present. Automatic rebuilds can be performed transparently with hot spares.With the revertible hot spares option users have the option of automatically migrating data back to the original drive position (when the failed drive has been replaced) or leaving data in place on the former hot-spare.

Flexible caching policies in PERC 6 RAID controllers allow administrators to tune cache writing schemes to help optimize performance or maximize data protection, including choosing between write-through caching and write-back caching.

PERC 6 controllers include features that can automatically track disk order and organization through disk roaming.

PERC 6 controllers also support moving physical disks from one cable connection or backplane slot to another on the same controller; the controllers can automatically recognize the relocated physical disks and logically place them in the appropriate virtual disks that are part of the disk group.

The Advanced Import feature enables administrators to import, or migrate, disk arrays created by a different PERC controller while the server remains online. The controllers can even import partial, or degraded, arrays and provide array preview capabilities before import to further enhance data serviceability.

PERC 6 controllers utilize Smart Cache Technology that offers administrators pre-tuned cache ratios for read and write operations that automate cache allocations based on the characteristics of the storage environment.

Administrators can also perform realtime RAID-level migration by converting one RAID level to a different RAID level.

PERC 6 enables enclosure firmware and hard disk drive firmware updated to be done while the system is online, reducing the impact to critical storage systems and enabling "on the fly" updates.

PERC 6 RAID controllers support global hot spare, dedicated hot spare, and affinity configurations, which administrators can set up using the Dell BIOS Configuration Utility as well as OMSA Storage Management. Global hot spares can typically be used in any degraded RAID array when the hot spare has sufficient capacity to fit into the RAID container. Dedicated hot spares are reserved for a particular disk group. The affinity option prioritizes a hot spare to the enclosure that it is located in.

Physical disk hot swapping allows administrators to manually substitute a replacement unit in a disk subsystem for a defective one while the subsystem is performing its normal functions.

The TBBU is a cache memory module with an integrated battery pack that enables administrators to transport the cache module with the battery into a different controller.

Native command queuing (NCQ) for SATA and tagged command queuing (TCQ) for SAS hard drives helps increase performance by allowing individual hard disks to optimize the order in which read and write commands are executed.