NVLog

This repository contains the prototype of the system NVLog (i.e. NVPC) we designed in the paper. NVLog is a transparent NVM write-ahead log for disk file systems. For more information, please refer to our paper: Boosting File Systems Elegantly: A Transparent NVM Write-ahead Log for Disk File Systems.

WARNING: Only use this work for experimental tests. DO NOT install it under production environment!

Artifacts Structure

Directory structure:

NVPC
├── ae                      --- Document and scripts for artifact evaluation
├── dev_vm                  --- Scripts to build kernel, etc.
├── linux-5.15.125          --- Our modified linux kernel
├── utils                   --- Scripts for diagrams and code for utilities
└── README.md               --- Doc you are watching

Artifact Evaluation

To swiftly evaluate the performance of NVLog, please refer to this link. It will guide you through the performance evaluation process in the environment we have prepared.

The following content provides instructions for building NVLog from scratch.

Getting Started

Now we will start guiding you step by step on how to deploy and run the code we've implemented in the repository.

Prerequisites

NVPC is implemented on kernel version 5.15.125. Make sure that your Linux distribution supports this kernel version if you want to install this kernel to your machine.

If you just want to test the functionality we have implemented in VM, the hardware required is as follows:

• CPU: x86_64 CPU with multiple cores
• Memory: 16GB+
• Disk: 200GB+
• Virtualization: KVM enabled
• QEMU version: 4.2.1+

But if you need to reproduce the evaluation part of our article, the hardware required is as follows:

• CPU: Intel Xeon 5218R

  or other Intel Xeon Processor (2nd Gen or later) with Intel Optane DCPMM support

• Memory: 128GB DDR4 ECC Memory

• NVM: 1st Gen Intel Optane DCPMM 256GB (128GB*2)

• Disk: Samsung PM9A3 (NVMe PCI-e 3.0 SSD 1.92TB)

  or any other disks, but the result may be different from our report in the paper

Installation

OS Setup

We run and evaluate our code on Linux distribution Ubuntu 20.04.6 LTS Server. When installing Ubuntu, just follow Ubuntu's installer instructions and try not to use the SWAP partition.

Once you have installed the operating system, you will need to use root for all operations to avoid permission-related issues.

Install Kernel

Make sure that you have the relevant tools installed to compile a Linux kernel.

• Move to utils/ndctl dir, make the ndctl toolchain first. This tool is a modified version to support NVPC, so you need to do this step even if you already have the relevant tools installed.

• Move to linux-5.15.125 dir, copy .config.example as .config. This is the example config file we provide. You can make some further modification on it if you want.

• Move to dev_vm dir and run ./make_kernel.sh. Check the output to see if the kernel is compiled successfully.

• If you want to use QEMU to evaluate NVPC:

  • Run build_vm.sh in dev_vm, it will prepare a QEMU VM for you with Ubuntu 20.04. Follow the step on the VM screen to install Ubuntu first.

  • When the VM is installed successfully, close it. Then run copy_kernel.sh. This script helps you to move the relevant files, including the compiled kernel, useful scripts, and utils, to the shared.img virtual disk, so that you can access it in the VM.

  • Run run_qemu.sh, it will start the VM with proper hardware settings.

  • Inside the VM, mount /dev/sdb (or other path that describes the shared.img vdisk). Then move to the mounted dir, run ./install_kernel.sh && reboot to install the kernel.

• If you want to install NVPC on your physical machine, just move to dev_vm dir, and run ./_install_kernel.sh && reboot.

Test Basic Functions

Note that deploying NVPC needs NVM devices, whether virtual or real hardwares. Be sure that you have NVM and the NVM is NOT IN USE and DOES NOT CONTAIN ANY USEFUL DATA. The following steps may erase and modify the data on the NVM.

Initialize NVPC

Move to the utils directory (utlis dir under this workspace for physical machine, or the utils dir under shared disk for VM), then run the init script ./nvpc_init.sh.

Or if you need to set up NVPC with specific configuration, modify the nvpc_init_default.conf in utils dir BEFORE running nvpc_init.sh.

Open NVPC on a Mount Point

Run ./nvpcctl open <path> under utils dir. This will open NVPC on the mount point file system of the given path.

Then all FS operations on the opened mount point will be handled by NVPC. E.g. write something to a file with sync, NVPC will absorb the sync (if absorb_syn is on in the configuration). ./nvpcctl usage will display the pages used by NVPC.