ndctl:tldr:407f4
The command "ndctl create-namespace --mode=${fsdax}" is used to create a new namespace, or a logical partition, on a Non-Volatile Memory (NVM) device using the ndctl utility.
Here is the breakdown of the components of the command:
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"ndctl": It refers to the ndctl utility, which is a command-line tool used for managing and configuring NVM devices, such as NVDIMMs (Non-Volatile Dual In-line Memory Modules).
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"create-namespace": This is the specific command within ndctl used to create a new namespace. A namespace represents a logical partition of the NVM device that can be utilized as a block device or a memory-mapped file.
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"--mode=${fsdax}": This is an option that specifies the mode of the namespace being created. The value is assigned to a variable named "fsdax". The "--mode" option accepts different modes, and in this case, the value of "fsdax" is used as the mode. "fsdax" stands for Filesystem Direct Access (DAX), which allows direct access to the NVM device without going through the filesystem cache. This mode is often preferred for applications that require direct access to the NVM device for better performance.
Overall, the command is creating a new namespace on an NVM device using ndctl, and configuring it to operate in the Filesystem Direct Access (DAX) mode.