Users Guide

Setting up redundant path support on the PERC H840 adapter
The PERC H840 card can detect and use redundant paths to disks contained in enclosures. With redundant paths to the same
device, if one path fails, another path can be used to communicate between the controller and the device.
To connect single enclosure, cable the ports so that the enclosure is connected to both the ports on the controller card. See
Figure 6. PERC H840 Card ports - Four enclosures with multipath configuration in PERC H840 enclosure support.
Profile Management
PERC 10 introduces the concept of profiles. A profile is user selectable. It defines controller queue depth and the maximum
number of physical and virtual disks. There are two profiles: PD64 and PD240. The H740 supports only the PD64 profile. The
H745P MX supports only the PD240 profile. The H840 supports both PD64 and PD240. PD240 is the default profile on H840.
For more information see Changing profile using HII Configuration Utility.
NOTE: When an H740 or H840 controller is upgraded to firmware version 50.3.0-1022 from an older firmware version, the
profile on the controller is set to PD64 by default.
Table 2. Supported Profiles on PERC 10
Feature PD64 PD240
Profile ID 10 12
Maximum physical disk supported 64 240
Maximum virtual disk supported 64 240
Controller queue depth 4096 3072
Maximum enclosure supported
● One enclosure using multipath
configuration
● Two enclosure using single path
configuration
● Four enclosure using multipath
configuration
● Eight enclosure using single path
configuration
NOTE: In the MX chassis, H745P MX supports seven enclosures using a multipath configuration.
NOTE: PD64 is supported on both internal and external controllers, whereas PD240 is supported only on the H840 and
H745P MX.
Secure firmware update
This feature provides a cryptographic method of updating the firmware using an RSA encryption-decryption algorithm.
Only Dell-certified firmware is supported on your PERC controller.
Snapdump
The Snapdump feature provides the Dell support team with the debug information which can help to find the cause of firmware
failure. In the instance of firmware failures, the firmware collects the logs and information at the time of failure, which are
stored in a compressed file called a snapdump.
Snapdumps are also generated manually to provide additional debug information. When a snapdump is generated, it is stored in
the controller's cache memory. This means in the event of a power loss the controller will offload the snapdump as part of its
cache preservation mechanism. Snapdumps are preserved by default through four reboots before its deleted.
To generate a snapdump, change the snapdump, delete a snapdump, and to download a stored snapdump settings, see Dell
EMC PowerEdge RAID Controller CLI Reference Guide at www.dell.com/storagecontrollermanuals.
Virtual disk features
This section lists the following virtual disk features supported on PERC 10 cards in detail:
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Features