Users Guide

Using disk roaming
About this task
Perform the following steps to use disk roaming:
Steps
1. Turn off the power to the system, physical disks, enclosures, and system components.
2. Disconnect power cables from the system.
3. Move the physical disks to desired positions on the backplane or the enclosure.
4. Perform a safety check. Make sure the physical disks are inserted properly.
5. Turn on the system.
Results
The controller detects the RAID configuration from the configuration data on the physical disks.
FastPath
FastPath is a feature that improves application performance by delivering high I/O per second (IOPs) for solid state drives
(SSD). The PERC 11 series of cards support FastPath.
To enable FastPath on a virtual disk, the cache policies of the RAID controller must be set to write-through and no read ahead.
This enables FastPath to use the proper data path through the controller based on command (read/write), I/O size, and RAID
type.
Non–RAID disks
A non–RAID disk is a single disk to the host, and not a RAID volume. The only supported cache policy for non–RAID disks is
Write-Through.
Physical disk power management
Physical disk power management is a power-saving feature of PERC 11 series cards. The feature allows disks to be spun down
based on disk configuration and I/O activity. The feature is supported on all rotating SAS and SATA disks, and includes
unconfigured and hot-spare disks. The physical disk power management feature is disabled by default. You can enable the
feature in the Dell Open Manage Storage Management application or in the Human Interface Infrastructure (HII) configuration
utility. For more information on HII configuration and physical disk power management, see Enabling physical disk power
management. For more information on using the Dell Open Manage Storage Management application, see the Dell OpenManage
documentation at www.dell.com/openmanagemanuals.
Profile Management
PERC 11 supports the PD240 profile. It defines controller queue depth and the maximum number of physical and virtual disks.
Table 3. Supported profile on PERC 11
Feature PD240
Profile ID 30
Maximum physical disk supported 240
Maximum virtual disk supported 240
Controller queue depth 5120
Features of PowerEdge RAID Controller 11 17