NBStack

Introduction

In short, NBStack is a storage system that provides an atomic write interface to user applications (like F2FS). Internally, NBStack eliminates file system ordered writes by giving access to the flash out-of-band area and organizing the blocks of an atomic write write back as a single linked list. Therefore, NBStack can achieve higher operations per second compared with F2FS.

For more information, please refer to our paper "Better atomic writes by exposing the flash out-of-band area to file systems" in LCTES 21.

Quick link:

• LCTES 21: https://pldi21.sigplan.org/home/LCTES-2021
• DOI link: https://doi.org/10.1145/3461648.3463843

Run NBStack

Prerequisites

Use FEMU to emulate an Open-Channel SSD for your QEMU virtual machine. We recommend FEMU commitID 464d8aab1810a738cd22187bd9a8ffd6a22c7683.

Linux Kernel version

Our implementation is based on Linux kernel 5.1.

Download NBStack

git clone https://github.com/WNLO-DSAL/NBStack

Tweaks for FEMU

Do the additional tweaks described in https://github.com/ucare-uchicago/FEMU/wiki/FEMU-Best-Practice.

Apply NBStack's kernel patch.

If your linux kernel source resides in /usr/src/kernels/linux, you can use our script to apply kernel patch.

cd NBStack
./patch_kernel.sh

Check out patch_kernel.sh for details.

Build kernel

Here's a nice article from kernelnewbies for buiding instructions.

Don't forget to enable lightNVM(NVM=y) and disable pblk(NVM_PBLK=n). After compilation, restart and login to the new kernel.

Install nvme cli

cd ~
git clone https://github.com/linux-nvme/nvme-cli
cd nvme-cli
make
make install

Build and launch qblk

cd /path/to/NBStack/src/qblk
make -j16
./install
# This will create a block device /dev/qblkdev
# Check out block devices
lsblk

Format file system

The physical format of NBFS and F2FS are the same. The following script works for both F2FS and NBFS.

cd /path/to/NBStack/src/qblk
./makef2fs
# This will format /dev/qblkdev as F2FS

Build and mount F2FS/NBFS

cd /path/to/NBStack/src/nbfs
vim nbfs.h

Modify the nbfs.h to choose the file system we wan't to run.

• F2FS: Comment out #define USE_NBFS
• NBFS-L: #define USE_NBFS + #define NBFS_DURABILITY_MODE (0)
• NBFS-D: #define USE_NBFS + #define NBFS_DURABILITY_MODE (1)
• NBFS-U: #define USE_NBFS + #define NBFS_ULTRAFAST_MODE

make -j16
./install
./mountnbfs
# This will create a directory /mnt/qhw and mount /dev/qblkdev to /mnt/qhw
# Check out the mount:
mount | grep qhw

Mobibench test

cd /path/to/NBStack
# Prepare for the tests
./preparetest.sh

cd scripts/lctes

# Push button tests
./mobibench.sh

SQLite test (task running time)

cd /path/to/NBStack

# Prepare for the tests
./preparetest.sh

cd evaluations/2-TaskRunningTime

# Follow the instructions to test.
cat README.md