Caio Raphael

They change how data is stored, not how users interact with it.
- From a user's perspective, all of these expose essentially the same abstraction.
- "Why are my files scattered everywhere?", "Why do applications create arbitrary folders?"
  - that's usually determined by:
    - the operating system
    - application conventions
    - desktop environment
    - package manager
    - standards like the FHS
  - —not by the filesystem.
They determine things like:
- How directories and files are organized.
- How free space is tracked.
- How permissions and metadata are stored.
- Whether the filesystem journals changes.
- Whether it supports snapshots, compression, checksums, etc.
They are not compatible with each other internally—an ext4 partition and an NTFS partition organize data completely differently.

Platform :
- Linux (OpenZFS)
  - Or OpenZFS ports for other Unix-like systems
- FreeBSD
- TrueNAS
Strengths :
- Copy-on-write
- End-to-end checksums
- Snapshots
- Clones
- Compression
- Deduplication
- Integrated RAID management (RAID-Z)
Weaknesses :
- High RAM usage, more complex
  - You need at least 1GB of RAM per 1TB of storage.
Common uses :
- Servers
- NAS systems
- Backup storage
It's not in the Linux kernel, due to licensing drama.
On-disk structure :
- Organizes storage into copy-on-write trees with checksummed blocks and storage pools.

Platform :
- Linux.
Strengths :
- Optimized for flash storage (SSDs/eMMC)
  - It will make your SSD last longer.
  - Reduce write amplification
  - Improve flash lifetime
  - Faster random writes
Weaknesses :
- Fewer advanced features than ZFS
Common uses :
- Android devices
- Embedded Linux
- Some desktop Linux installations
On-disk structure :
- Is log-structured for flash devices.

Is a modern Linux filesystem designed to provide many of the advanced features found in ZFS while remaining integrated with the Linux kernel.
Strengths :
- Copy-on-write (CoW)
- Snapshots
- Writable clones
- Checksums for data and metadata
- Transparent compression (zstd, lzo, zlib)
- Subvolumes
- Online resizing
- Built-in RAID support
- Send/receive for efficient incremental backups
Weaknesses :
- RAID 5/6 is still not recommended for production in many cases; more complex than ext4
Common uses :
- Desktop Linux
- Rolling-release distributions
- Development machines
- Systems where snapshots are useful
On-disk structure :
- Stores almost everything in B-trees (balanced trees), which is where its name comes from.
- The main trees include:
  - Filesystem tree — files, directories, and inodes
  - Extent tree — tracks which data blocks (extents) are allocated
  - Checksum tree — stores checksums for data blocks
  - Chunk tree — maps logical filesystem addresses to physical devices
  - Root tree — tracks subvolumes and snapshots
  - Device tree — information about storage devices

Platform :
- Linux.
Strengths :
- Excellent for large files and parallel I/O
Weaknesses :
- A XFS partition can never shrink, only grow.
- Terrible with tiny files.
Common uses :
- Enterprise Linux
- Media production
- Databases
On-disk structure :
- Uses B+ trees extensively.

Default Windows filesystem.
Platform :
- Windows.
- Linux, via special driver.
  - Read support has existed for years.
  - Modern kernels include the NTFS3 driver for read/write support.
- macOS
  - Reads NTFS natively.
  - Writing generally requires third-party software.
Strengths :
- Journaling
- ACL permissions
- Compression
- Encryption (EFS)
- Sparse files
- Hard links
Weaknesses :
- It works on linux, but not ideal.
  - Not great on performance.
  - Native Linux write support relies on NTFS3/FUSE implementations
On-disk structure :
- Stores metadata in the Master File Table (MFT).

Platform :
- Almost everything
Strengths :
- Universal compatibility.
Weaknesses :
- 4 GB max file size, 2 TB practical volume limit
Common uses :
- BIOS/UEFI boot partitions
- Small USB drives
- Embedded devices
On-disk structure :
- Stores allocation information in a File Allocation Table.