USFS - unsigned short file system

Let's trip back to the 80s and save our modern files in 8.3 filename convention.

Calculate SHA-256 of file name, take 16 bits of it and use this unsigned short as a new name. And one more file for metadata (original file name, modification time)

Octal encoding give file names 000000 - 177777 and excitingly high chance of collision.

USFS release notes and roadmap

Tests:

1. small - 799 files, 46 folders, 2.14 MiB - spring-core-4.3.25.RELEASE.jar file content
2. fat - 30 files, 1 folder, 1 GiB - hi-res pictures, jdk and idea archives

Write (seconds) / Read (after write, presumably cached, seconds) / Delete (seconds)

• file system - s:44/17/19, f:7/4/0
• mongo gridfs - s:204/33/36, f:44/26/1
• mongo gridusfs - s:213/33/39, f:35/25/1
• in-memory - s:21/16/16, f:6/3/0

Usage example:

sudo apt install dosfstools
dd if=/dev/zero of=/tmp/usfs.dos bs=1M count=1200
sudo mkfs.msdos /tmp/usfs.dos
mkdir /tmp/usfs
sudo mount -t msdos -o loop,umask=000,check=s,tz=UTC /tmp/usfs.dos /tmp/usfs
sudo docker run -d --rm --name usfs -v /tmp/usfs:/mnt -p 21:21 -p 1024:1024 abalanonline/usfs