Installation FAQ

Short answers to the most common installer questions. For full steps see Overview, Requirements, and Quick-Start.

1. Do I need Linux installed first?

No. Boot the live USB / ISO directly — no host OS required.

Flash the image from any OS (Linux dd, Windows Rufus in DD mode), boot it, and install from the live session. See Requirements and Install on Real Hardware.

2. Can I try Forest OS without installing?

Yes. Live mode runs entirely from RAM + USB/ISO and touches nothing on internal disks.

Pick Forest OS in the ForeB menu to try it, or test first in a VM. See Quick-Start and Install on a VM.

3. Will installing erase Windows?

Only the disk you select as target. Other disks are left alone.

forinstall wipes the target disk you confirm — check size/model with fdisk -l / blkid first, back up, and unplug extra disks if unsure. See Install Guide (UEFI), Install Guide (BIOS), Disk Tools.

4. FAT vs ext2 — which filesystem should I pick?

FAT for writable/UEFI-compatible stores, ext2 for Unix-style roots (currently read-only in the kernel).

FAT32 has full read/write (fern/src/fat.c); kernel ext2/3/4 is read-only and some configs disable it. Default VM/internal installs use ext2; use FAT where you need ESP sharing or writable USB persistence. See Choosing a Filesystem, Filesystems, USB Persistence.

5. Can I install to a USB stick?

Yes — a full USB install treats the stick as the disk.

Pick the USB device as the install target in forinstall; everything (system + /home + /etc) lives on the stick and boots without an internal disk. See USB Persistence and Install Guide (UEFI).

6. Does installation need internet?

No. Installation is fully offline.

Kernel, initrd, base userspace, and ForeB stages all come from the install media. You only need a network later for pac packages. See Overview.

7. What about Secure Boot?

Turn Secure Boot off. The shipped BOOTX64.EFI is unsigned and firmware will reject it otherwise.

There is no signed shim / MOK to enroll — disabling is required. See Install Guide (UEFI), UEFI Boot, Install on Real Hardware.

8. How big does the target disk need to be?

2 GB minimum, 8 GB+ recommended.

Base system + initrd needs ~100–200 MiB free after install (df -h to confirm); small 512 MiB targets fill up during copy, large USB/HDD leaves room for packages and /home. See Requirements, USB Persistence.

9. Can I update after installing?

Yes, with forupdate / pac update.

pac list
pac update
pac update <pkg>
pac history

Needs a route to /etc/pacservers (plain HTTP — trusted networks only). See Post-Install.

Offline upgrades: see Updates (forupdate from local media with manifest, backup, and rollback).

10. Can I remove Forest OS again?

Yes. Wipe the partitions / restore your previous bootloader — nothing locks the disk.

Boot other media, repartition with fdisk, reformat, and reinstall the other OS bootloader if needed. Back up first; dd to the wrong device is irreversible. See Troubleshooting, Disk Tools, Remove / Uninstall.

11. Why are some filesystems read-only?

Driver maturity. Only FAT has a production write path today.

ISO9660/UDF/exFAT are probe/mount-only, ext2/3/4 and btrfs are read-only/best-effort, tmpfs/initrd are RAM-only. Workaround: keep writable data on FAT32 (persistent USB) or an ext2 root created by the installer/mkfs. See Filesystems, Choosing a Filesystem.

12. Where do I get help when install fails?

Capture the serial log, then check the wiki.

Keep -serial stdio (QEMU) or a serial cable on hardware — kernel banners, panics, and forinstall errors land there; paste the last ~20 lines in bug reports. See Troubleshooting, Troubleshooting, First Boot.

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