tifs-on-tifs

Run TiFS (on TiKV) on TiFS

Why would you do this?

As with most of my random projects, this started as a combination of boredom and "because I could". This serves almost no practical purpose, but it does show off TiFS with a real world use case.

What is TiFS?

TiFS is a POSIX filesystem driver implemented on top of TiKV.

https://pingcap.com/blog/tifs-a-tikv-based-partition-tolerant-strictly-consistent-file-system

How do I use it?

Start the first tier PD and TiKV.

$ docker-compose up -d pd0 tikv0

Mount the first tier TiFS.

$ docker-compose up -d tifs0

Make sure the mount succeeded.

$ mount | grep mnt/tifs0

Start the second tier PD and TiKV.

$ docker-compose up -d pd1 tikv1

Mount the second tier TiFS.

$ docker-compose up -d tifs1

Make sure the mount succeeded.

$ mount | grep mnt/tifs1

Cleaning up

Stop the containers.

$ docker-compose down

Unmount the filesystems.

$ sudo umount -f /mnt/tifs0 /mnt/tifs1

Remove the mount dirs.

$ sudo rm -rf /mnt/tifs0 /mnt/tifs1

How well does it perform?

This setup has terrible performance, but that's not really the point.

First tier TiFS:

$ time dd if=/dev/zero of=/mnt/tifs0/big.file bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB, 100 MiB) copied, 39.9818 s, 2.6 MB/s

real    0m40.077s
user    0m0.000s
sys     0m0.082s

Second tier TiFS: