Intel Optane DC Persistent Memory - Configuration and Setup White Paper

4TECHNICAL WHITE PAPER
CONTENTS & NAVIGATION
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The storage capacities in one or more DCPMMs in a set are grouped into a region.
– Often, a region is created across the DCPMMs in the set, thus creating an interleaved set
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To be useful, a region is subdivided into one or more namespaces.
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Namespaces can have a capability identied as BTT (Block Translation Table).
– BTT namespaces support ordinary le systems in the OS because the BTT allows the OS to see
the DCPMM storage like a normal block-oriented device
– Non-BTT namespaces (also called PM namespaces) are used in App Direct Mode
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In the OS, namespaces appear as raw storage devices that can be partitioned into volumes and formatted.
– The DAX attribute can be attached to the volume. Details on doing this are covered in the procedural
appendices for Windows and Linux
Additional Notes about Storage Mode
• DCPMM are compatible with legacy/existing applications when using a PMEM-aware OS.
• When multiple DCPMMs are used on a processor, they should be congured to be interleaved for maximum
performance.
• In Storage Mode, the DCPMMs are only interleaved on a single processor. If DCPMMs are distributed across two
processors, there will be two independent storage devices.
• When interleaved, it is important to know the exact loading of DCPMM. If the DIMMs need to be removed
from the motherboard for any reason, (for example, motherboard replacements) make sure that the exact
location of each DIMM is known. Not placing the DCPMMs back in the exact Memory Slot will make the storage
data unreadable and may make it dicult to recover the data.
• Adding DCPMMs or changing congurations requires additional steps not normally associated with adding
or changing legacy storage devices.
• Storage Capacity available to the System will be slightly less than advertised capacity, for example:
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128 GB provides approximately 126 GB available capacity.
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256 GB provides approximately 252 GB available capacity.
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512 GB provides approximately 502 GB available capacity.
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Note: Additional overhead capacity may be required for: Regions, Namespace, and File System.
• In Storage Mode, DRAM memory acts like regular system memory.
• See Appendix A through D for more details on how to congure.
• Further notes regarding DAX (Direct Access):
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If your Windows system was ordered with DCPMM congured in Storage Mode, your DCPMM
will be formatted with a DAX aware le system.
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If your Linux-Ready system was ordered with DCPMM congured in Storage Mode, your DCPMM
will be congured for Storage Mode, but will be unformatted. You will be required to format the DCPMM
devices on your own. Instructions on conguring a Linux le system to be DAX-aware can be found in
Appendix C.
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For Windows:
– PowerShell is required to enable DAX
– DAX is only supported with NTFS on Windows systems
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For Linux:
– A terminal emulator and root permissions are required to enable DAX
– DAX is only supported with DAX-enabled le systems such as EXT4 on Linux
> Check your le system documentation to nd which le systems are DAX enabled
and at what version.
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A format operation is required to convert between DAX and non-DAX.
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Software encryption is not available, for example BitLocker.
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Software compression of the volume is not available.
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Existing lter drivers will not function.
Additional notes about Memory Mode
• As noted earlier, DRAM is required when conguring DCPMM in Memory Mode. The DRAM DIMMs are used
as cache for the DCPMM. HP recommends a ratio of 1:8 for DRAM capacity to DCPMM capacity.
• Memory available to the System will be slightly less than advertised capacity, for example:
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128 GB provides approximately 126 GB available capacity.
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256 GB provides approximately 252 GB available capacity.
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512 GB provides approximately 502 GB available capacity.
1
Introduction
5
DCPMM Security
Overview
System Requirements
6
System Setup Overview
8
Appendices