Partitioning and filesystems
Partitioning determines where system data is stored and limits boot, encryption, hibernation and snapshot choices. Back up important data before changing partitions.
Partition table
| Environment | Recommendation | Notes |
|---|---|---|
| Modern UEFI system | GPT | Supports every CatOS UEFI boot method |
| Windows 10/11 dual boot | GPT | Use the same firmware mode as Windows |
| Legacy BIOS | MBR or GPT | GRUB only; GPT may need a BIOS Boot partition |
| Limine | GPT | Current CatOS profile requires UEFI + GPT |
| systemd-boot, UKI, EFI Stub | GPT | UEFI only |
Do not mix UEFI and legacy BIOS on the same dual-boot installation.
Installation methods
- Erase disk: simplest option, destroys all data on the target disk.
- Install alongside: shrinks an existing partition for dual boot.
- Replace a partition: formats one selected partition.
- Manual partitioning: required for custom layouts, reused ESPs and advanced dual boot.
Manual partitioning
A UEFI installation needs:
- a FAT32 EFI System Partition mounted at
/boot/efi; - a root filesystem mounted at
/; - optional swap.
An existing Windows ESP can usually be reused without formatting. Verify its free space first.
EFI System Partition size
| Boot method | Minimum | Recommended |
|---|---|---|
| GRUB | 300 MiB | 300 MiB or more |
| Limine | 1 GiB | 2 GiB |
| systemd-boot | 1 GiB | 2 GiB |
| UKI | 1 GiB | 2 GiB |
| EFI Stub | 1 GiB | 2 GiB |
Non-GRUB methods may store kernels, initramfs files or UKIs in the ESP and therefore need more space.
Filesystems
The installer offers Btrfs, ext4, ext3, JFS, XFS and F2FS.
- Btrfs: CatOS default; supports subvolumes, Snapper and bootable snapshots with supported boot methods.
- ext4: simple and broadly compatible; no CatOS Btrfs snapshot integration.
- XFS: for experienced users who understand its management and shrinking limitations.
- F2FS: for specific flash-storage workloads, not automatically better for every SSD.
- ext3 and JFS: compatibility choices, not recommended for a new general desktop installation.
Snapshots are not backups and do not protect against disk failure.
Separate /home
A separate /home partition is optional. It can simplify retaining user files during reinstallation, but user configuration can still cause compatibility issues and the partition still needs a backup. For a normal Btrfs installation, subvolumes are often more flexible.
Swap
Available choices are no swap, a small swap partition, swap sized for hibernation and a swap file.
- Use hibernation-sized swap when you need suspend-to-disk.
- A swap file or small swap is suitable for ordinary desktop use.
- Low-memory systems should not disable swap without understanding out-of-memory behavior.