# Test Case: zstd Compression Level 1

**Test ID**: TC105-zstd-level1  

**G5 fixture contract**: Use [G5-MANUAL-SETUP.md](G5-MANUAL-SETUP.md).
Its generated paths, source comparisons, structured corruption offsets, and
cleanup rules supersede placeholder examples in this file.
**Category**: Compression  
**Priority**: High  
**Regression**: None

## Objective
Verify zstd compressed data path with level 1 (fastest) compression.

## Preconditions
- EROFS image created with zstd level 1: `mkfs.erofs -zzstd,level=1 test.img src/`
- Test files of various sizes
- FreeBSD 13.0+ with libzstd

## Test Steps
1. Create image with zstd level 1 compression
2. Attach and mount: `unit=$(mdconfig -a -t vnode -f test.img); mount -t erofs -o ro /dev/${unit} /mnt`
3. Read files and verify content
4. Test random access patterns
5. Measure throughput

## Expected Results
- All files decompress correctly
- Fast decompression speed
- Good compression ratio even at level 1
- Random access works correctly

## Verification Method
- SHA256 checksums match originals
- Decompression throughput > 200 MB/s
- No zstd decompression errors
- Random reads succeed

## Cleanup
```sh
umount /mnt
mdconfig -d -u "${unit}"
```

## Notes
Tests feature 59: zstd compressed data path with fast compression.
