What causes "llama.cpp: failed to mmap GGUF file"?

llama.cpp uses memory-mapped I/O to load GGUF files efficiently. The mmap fails when: - The file is incomplete (interrupted download) - The path contains spaces or non-ASCII characters and isn't quoted - File permissions block the user (read-only mount, root-owned file in user shell) - Filesystem doesn't support mmap (some network shares)

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Model format / GGUF

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llama.cpp: failed to mmap GGUF file

Q: How do you fix "llama.cpp: failed to mmap GGUF file"?

**Re-download** if the file may be partial: ```bash hf download TheBloke/Llama-2-7B-Chat-GGUF llama-2-7b-chat.Q4_K_M.gguf # or ollama pull llama3.1:8b ``` Verify with the published size from the model card. **Quote the path** if it has spaces: ```bash ./main -m "/Users/me/My Models/llama-3.1-8b.gguf" ``` **Fix permissions:** ```bash chmod 644 model.gguf ``` **Move off network shares.** GGUF mmap doesn't work reliably on SMB/NFS — copy the file to local disk first. **Disable mmap** as a workaround (uses more RAM but bypasses the issue): ```bash ./main -m model.gguf --no-mmap ```

llama_model_load: error loading model: failed to open ... or mmap

By Fredoline Eruo · Last verified May 6, 2026

Cause

llama.cpp uses memory-mapped I/O to load GGUF files efficiently. The mmap fails when:

The file is incomplete (interrupted download)
The path contains spaces or non-ASCII characters and isn't quoted
File permissions block the user (read-only mount, root-owned file in user shell)
Filesystem doesn't support mmap (some network shares)

Solution

Re-download if the file may be partial:

hf download TheBloke/Llama-2-7B-Chat-GGUF llama-2-7b-chat.Q4_K_M.gguf
# or
ollama pull llama3.1:8b

Verify with the published size from the model card.

Quote the path if it has spaces:

./main -m "/Users/me/My Models/llama-3.1-8b.gguf"

Fix permissions:

chmod 644 model.gguf

Move off network shares. GGUF mmap doesn't work reliably on SMB/NFS — copy the file to local disk first.

Disable mmap as a workaround (uses more RAM but bypasses the issue):

./main -m model.gguf --no-mmap

Did this fix it?

If your case was different, email hello@runlocalai.co with what you saw and we'll update the page. If it worked but took different commands on your platform, we want to know that too.