Persistent Memory Simulator

[Sarthak Prabhudas Makhija]

Hello,

Could be a naive question - 

Is there a way to run pmem simulator in a docker container? Or, is building linux kernel from the source the only way to get started with pmem simulator?

Regards

[Steve Scargall]

Hi Sarthak.

Containers use the same Kernel as the host OS, so you'll need to verify it supports PMem. See How To Verify Linux Kernel Support for Persistent Memory. PMem/NVDIMM support was added to the mainline 4.x Kernel and introduced in CentOS/RHEL 7.6 or later (their 3.x kernel). If you're using a recent OS (something released in the past 2-3yrs), you should have the necessary feature(s) available.  If you build your own Kernel, you'll want to verify the PMem/NVDIMM features were configured and enabled (see the link). For the Intel Optane Persistent Memory technology, see the Compatible Operating System OS for Intel Optane Persistent Memory matrix. 

There's no PMem simulator that I'm aware of, but a Linux Kernel that supports PMem/NVDIMM has the ability to use DRAM to emulate PMem. See Using the memmap Kernel option for instructions. Once the /dev/pmem devices are created, you can pass them through to the container. This option is good for testing and development, but not for performance testing or production as the data is volatile (backed by DRAM). 

Virtual Machines have greater flexibility over Containers in the context of emulating PMem. See Using KVM/QEMU Virtualization for instructions to configure an environment. You can use DDR + the kernel memmap option or a disk to emulate PMem from the host and pass it through to the guest, or the memmap option within the guest VM. 

Containers running on a system with physical PMem can use OpenShift or Kubernetes with the PMem-CSI plugin. 

[Sarthak Prabhudas Makhija]

Thank you Steve for the reply.

I tried with a VM running ubuntu21 which supports Pmem and it worked. Thank you again.

Regards

Sarthak Makhija