SlowFS

SlowFS is a FUSE filesystem written in Go to simulate physical media for testing purposes. SlowFS works by mirroring a backing directory to another directory, and then making accesses to files in that directory take a specified amount of time. SlowFS can model things like seek time, throughput, sequential / non- sequential accesses, et. cetera.

For addition details, run SlowFS with the help flag: slowfs --help

This is not an official Google product.

Basic Usage

Example invocation: slowfs --backing-dir=my-backing-dir --mount-dir=my-mount-dir

Configuration Files

You can specify an optional configuration file listing configurations in JSON, and then pass that as an argument.

[
  {
    "Name": "fast",
    "SeekWindow": "16KiB",
    "SeekTime": "8ms",
    "ReadBytesPerSecond": "100MiB",
    "WriteBytesPerSecond": "100MiB",
    "AllocateBytesPerSecond": "4GiB",
    "RequestReorderMaxDelay": "100us",
    "FsyncStrategy": "wbc",
    "WriteStrategy": "fastwrite",
    "MetadataOpTime": "500us"
  }
]

Example invocation:

  --config-file=my-config-file.json --config-name=fast```

###Overriding Values

You can also override any option through the corresponding command line flag.
For example, if you would like to change seek time:
```slowfs --backing-dir=my-backing-dir --mount-dir=my-mount-dir \
  --config-file=my-config-file.json --config-name=fast --seek-time=16ms```