PowerProtect: DD6400 FS create may fail due to disk error condition

Summary: The 8TB hard drives in the DD6400 head unit undergo a secure erase procedure in manufacturing. For some drive models, this creates a condition where added protection information about the drive becomes out of sync and can cause the drive to return an error if the system attempts to read sectors that have not been rewritten. The affected DDOS versions allow the I/O path to use such added modes of operation but do not rely on them as the RAID and DDFS provide protection beyond what the drives offer. It is possible that the DD6400 FS may fail to be created or may become unavailable in the case that three or more drives report this error for the same RAID 6 stripe, as it causes the RAID driver to take the RAID group offline to protect the system. ...

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Instructions

Affected Systems:

PowerProtect DD6400 ONLY
Data Domain Operating System (DDOS) versions 7.7.0.x, 7.7.1.0, and 7.8.0.x

Resolution:
The general resolution is to disable the use of the unneeded drive level checks. This makes the communication to the head unit drives the same as the drives in any external enclosures.

For field systems running the affected versions of DDOS, a customer installable Minimally Disruptive Update RPM is available.

MDU Installation Instructions:
This MDU, which is delivered as an RPM package, applies a script that is periodically run to switch a per-drive setting that instructs the I/O stack to send traditional commands that do not use the drive's DIF checks. There is no service disruption and no downtime associated with applying this MDU. This script does not impact the system performance.

Note: DDOS does not use DIF, even though some drives can use it.

IMPORTANT NOTES:

This MDU is only applicable to DD6400 with DDOS version 7.7.1 or 7.8.0.0.
If DDOS version 7.7.0 is installed, upgrade to 7.7.1 or 7.8.0.0 first.
If the system is upgraded from 7.7.1 to 7.8.0, this MDU RPM must be reinstalled.
The MDU RPM does not need to be reapplied if the system is upgraded to any other DDOS version which has the fix. (DDOS version 7.7.2 or 7.9.0)
Contact Dell Technical Support with questions or request for help with this procedure.

Installation Steps:

Download the mdu_diskdifpatch.rpm file.
Make a note of the following checksum information.

SHA 256: 7c7085350414b92d3c5d368f0f17f4ee0b8500faed6d6a1f829a99cee12ac85a
MD5: b30255a5e7328732a001bc6170108ebe
Log in to the DD6400 System Manager UI as a "sysadmin" user.
Go to "Maintenance > System > Upload Upgrade Package" and select the mdu_diskdifpatch.rpm file and click OK.
Select the mdu_diskdifpatch.rpm and click "View Checksum" to verify the checksum. Ensure the checksums match with the information noted down in #2.
If the checksums match, click "Close" and proceed with the installation of the MDU package by clicking the "Perform System Upgrade" button.

It takes a few minutes to apply the MDU. There is no system reboot required.