instruction: Create a Dockerfile for fundamentals
output: ```dockerfile
  from these
  draw-backs unless /var/lib/docker/volumes/ isn't backed by Btrfs.Page cachingBtrfs doesn't support page cache sharing. This means that each process
  accessing the same file copies the file into the Docker host's memory. As a
  result, the btrfs driver may not be the best choice for high-density use cases
  such as PaaS.Small writesContainers performing lots of small writes (this usage pattern matches what
  happens when you start and stop many containers in a short period of time, as
  well) can lead to poor use of Btrfs chunks. This can prematurely fill the Btrfs
  filesystem and lead to out-of-space conditions on your Docker host. Use btrfs filesys show to closely monitor the amount of free space on your Btrfs device.Sequential writesBtrfs uses a journaling technique when writing to disk. This can impact the
  performance of sequential writes, reducing performance by up to 50%.FragmentationFragmentation is a natural byproduct of copy-on-write filesystems like Btrfs.
  Many small random writes can compound this issue. Fragmentation can manifest as
  CPU spikes when using SSDs or head thrashing when using spinning disks. Either
  of these issues can harm performance.If your Linux kernel version is 3.9 or higher, you can enable the autodefrag
  feature when mounting a Btrfs volume. Test this feature on your own workloads
  before deploying it into production, as some tests have shown a negative impact
  on performance.SSD performanceBtrfs includes native optimizations for SSD media. To enable these features,
  mount the Btrfs filesystem with the -o ssd mount option. These optimizations
  include enhanced SSD write performance by avoiding optimization such as seek
  optimizations that don't apply to solid-state media.Balance Btrfs filesystems oftenUse operating system utilities such as a cron job to balance the Btrfs
  filesystem regularly, during non-peak hours. This reclaims unallocated blocks
  and helps to prevent the filesystem
  ```