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Overview

Borg UI provides fast archive browsing with intelligent Redis caching that dramatically improves performance for large repositories. Navigate through backup archives, preview files, and restore individual files or entire directories.

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Redis Caching (600x Faster)

Archive browsing uses Redis caching to accelerate file listings: 
# From browse.py:23-255
MAX_ITEMS_IN_MEMORY = 1_000_000  # Maximum items to load
MAX_ESTIMATED_MEMORY_MB = 1024   # 1GB memory limit
ITEM_SIZE_ESTIMATE = 200         # Average bytes per item

@router.get("/{repository_id}/{archive_name}")
async def browse_archive_contents(
    repository_id: int,
    archive_name: str,
    path: str = Query("", description="Path within archive"),
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    # Check cache first
    all_items = await archive_cache.get(repository_id, archive_name)
    
    if all_items is not None:
        logger.info("Using cached archive contents",
                   archive=archive_name,
                   items_count=len(all_items))
Performance Improvement: First browse loads from Borg (slow), subsequent browses use Redis cache (600x faster). Cache is automatically invalidated when archives change.

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Memory Safety

Borg UI protects against out-of-memory errors when browsing large archives: 
# From browse.py:52-75
result = await borg.list_archive_contents(
    repository.path,
    archive_name,
    path="",
    remote_path=repository.remote_path,
    passphrase=repository.passphrase,
    max_lines=max_items,  # Kill borg process if limit exceeded
    bypass_lock=repository.bypass_lock
)

# Check if line limit was exceeded
if result.get("line_count_exceeded"):
    lines_read = result.get("lines_read", 0)
    raise HTTPException(
        status_code=413,
        detail=f"Archive is too large to browse (>{lines_read:,} files). "
               f"Maximum supported: {max_items:,} files. "
               f"You can increase this limit in Settings > System."
    )
Configurable Limits:
  • browse_max_items: Maximum files to load (default: 1,000,000)
  • browse_max_memory_mb: Maximum memory usage (default: 1024 MB)
For archives with millions of files, consider using command-line tools or increasing memory limits in Settings > System.

​
Browsing Archives

1

List Available Archives

Get all archives in a repository:
GET /api/archives/list?repository=<repo_path>

# From archives.py:22-58
@router.get("/list")
async def list_archives(
    repository: str,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    result = await borg.list_archives(
        repository,
        remote_path=repo.remote_path,
        passphrase=repo.passphrase,
        bypass_lock=repo.bypass_lock
    )
Response:
{
  "archives": [
    {
      "name": "prod-2026-02-28T10:30:00",
      "time": "2026-02-28T10:30:00.000000",
      "id": "a1b2c3d4e5f6"
    },
    {
      "name": "prod-2026-02-27T10:30:00",
      "time": "2026-02-27T10:30:00.000000",
      "id": "f6e5d4c3b2a1"
    }
  ]
}
2

Browse Archive Contents

Navigate through the archive filesystem:
GET /api/browse/{repository_id}/{archive_name}?path=/var/www
Response:
{
  "items": [
    {
      "name": "html",
      "type": "directory",
      "size": 524288000,
      "path": "var/www/html",
      "mtime": "2026-02-28T10:25:00"
    },
    {
      "name": "index.php",
      "type": "file",
      "size": 2048,
      "path": "var/www/index.php",
      "mtime": "2026-02-28T09:15:00"
    }
  ]
}
3

Get Archive Details

View detailed information about an archive:
GET /api/archives/{archive_id}/info?repository=<repo_path>&include_files=true&file_limit=1000

# From archives.py:60-180
@router.get("/{archive_id}/info")
async def get_archive_info(
    repository: str,
    archive_id: str,
    include_files: bool = False,
    file_limit: int = 1000,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):

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Archive Information

Get comprehensive metadata about an archive: 
{
  "info": {
    "name": "prod-2026-02-28T10:30:00",
    "id": "a1b2c3d4e5f6",
    "start": "2026-02-28T10:30:00",
    "end": "2026-02-28T10:45:30",
    "duration": 930.5,
    "stats": {
      "original_size": 1073741824,
      "compressed_size": 644245094,
      "deduplicated_size": 214748364,
      "nfiles": 2500
    },
    "command_line": [
      "borg", "create",
      "--stats", "--json", "--progress",
      "::prod-2026-02-28T10:30:00",
      "/var/www", "/etc/nginx"
    ],
    "hostname": "web-server-01",
    "username": "root",
    "chunker_params": "19,23,21,4095",
    "repository": {
      "id": "abc123",
      "location": "ssh://[email protected]/backups/prod"
    },
    "encryption": {
      "mode": "repokey-blake2"
    }
  }
}

# From archives.py:92-125
enhanced_info = {
    "name": archive_info.get("name"),
    "id": archive_info.get("id"),
    "start": archive_info.get("start"),
    "end": archive_info.get("end"),
    "duration": archive_info.get("duration"),
    "stats": archive_info.get("stats", {}),
    "command_line": archive_info.get("command_line", []),
    "hostname": archive_info.get("hostname"),
    "username": archive_info.get("username"),
    "chunker_params": archive_info.get("chunker_params"),
    "repository": archive_data.get("repository", {}),
    "encryption": archive_data.get("encryption", {}),
    "cache": archive_data.get("cache", {})
}

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Directory Size Calculation

Borg UI calculates directory sizes recursively: 
# From browse.py:133-161
def calculate_directory_size(dir_path: str) -> int:
    """Calculate total size of all files in a directory recursively"""
    total_size = 0
    file_count = 0
    search_prefix = f"{dir_path}/" if dir_path else ""
    
    for item in all_items:
        item_path = item["path"]
        # Check if this item is under the directory
        if search_prefix:
            if item_path.startswith(search_prefix) or item_path == dir_path:
                # Only count files, not directories
                if item.get("type") != "d" and item.get("size") is not None:
                    total_size += item.get("size", 0)
                    file_count += 1
    
    return total_size
Example: 
/var/www/
├── html/          (500 MB - calculated from contents)
│   ├── images/    (300 MB)
│   └── css/       (200 MB)
└── logs/          (50 MB)

​
File Restoration

​
Download Individual Files

GET /api/archives/download?repository=<repo>&archive=<name>&file_path=<path>&token=<auth>

# From archives.py:294-391
@router.get("/download")
async def download_file_from_archive(
    repository: str,
    archive: str,
    file_path: str,
    token: str,
    db: Session = Depends(get_db)
):
    # Create temporary directory for extraction
    temp_dir = tempfile.mkdtemp()
    
    try:
        # Extract the specific file
        result = await borg.extract_archive(
            repository,
            archive,
            [file_path],
            temp_dir,
            dry_run=False,
            remote_path=repo.remote_path,
            passphrase=repo.passphrase,
            bypass_lock=repo.bypass_lock
        )
        
        # Return file as download
        return FileResponse(
            path=extracted_file_path,
            filename=filename,
            media_type='application/octet-stream'
        )
1

Select File

Navigate to the file in the archive browser.
2

Extract File

Borg UI extracts the file to a temporary directory:
borg extract ::archive-name path/to/file
3

Download

File is served as a download and temporary files are cleaned up.

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Deleting Archives

Remove old archives to free up space: 
DELETE /api/archives/{archive_id}?repository=<repo_path>

# From archives.py:224-292
@router.delete("/{archive_id}")
async def delete_archive(
    repository: str,
    archive_id: str,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    # Validate admin access
    if not current_user.is_admin:
        raise HTTPException(status_code=403, detail="Admin access required")
    
    # Check if there's already a running delete job
    running_job = db.query(DeleteArchiveJob).filter(
        DeleteArchiveJob.repository_id == repo.id,
        DeleteArchiveJob.archive_name == archive_id,
        DeleteArchiveJob.status == "running"
    ).first()
    
    if running_job:
        raise HTTPException(
            status_code=409,
            detail=f"Delete operation already running (Job ID: {running_job.id})"
        )
    
    # Create delete job record
    delete_job = DeleteArchiveJob(
        repository_id=repo.id,
        repository_path=repo.path,
        archive_name=archive_id,
        status="pending"
    )
    db.add(delete_job)
    db.commit()
    
    # Execute delete asynchronously
    asyncio.create_task(
        delete_archive_service.execute_delete(
            delete_job.id,
            repo.id,
            archive_id,
            None  # New session for background task
        )
    )
Response: 
{
  "job_id": 456,
  "status": "pending",
  "message": "Archive deletion started in background"
}
Deleting archives is permanent! Ensure you no longer need the data before deletion. Consider using borg prune with retention policies instead.

​
Delete Job Status

Monitor archive deletion progress: 
GET /api/archives/delete-jobs/{job_id}

# From archives.py:394-432
@router.get("/delete-jobs/{job_id}")
async def get_delete_job_status(
    job_id: int,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    job = db.query(DeleteArchiveJob).filter(DeleteArchiveJob.id == job_id).first()
    
    # Read log file if it exists
    logs = None
    if job.log_file_path and os.path.exists(job.log_file_path):
        with open(job.log_file_path, 'r') as f:
            logs = f.read()
Response: 
{
  "id": 456,
  "repository_id": 1,
  "archive_name": "prod-2026-02-01T10:30:00",
  "status": "completed",
  "started_at": "2026-02-28T11:00:00Z",
  "completed_at": "2026-02-28T11:15:00Z",
  "progress": 100,
  "progress_message": "Archive deleted successfully",
  "has_logs": true
}

​
Cancel Delete Operation

POST /api/archives/delete-jobs/{job_id}/cancel

# From archives.py:434-451
@router.post("/delete-jobs/{job_id}/cancel")
async def cancel_delete_job(
    job_id: int,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    if not current_user.is_admin:
        raise HTTPException(status_code=403, detail="Admin access required")
    
    await delete_archive_service.cancel_delete(job_id, db)

​
Cache Management

Redis cache stores parsed archive listings: 
# From browse.py:122-131
# Store in cache
cache_success = await archive_cache.set(repository_id, archive_name, all_items)
if cache_success:
    logger.info("Cached archive contents",
               archive=archive_name,
               items_count=len(all_items))
else:
    logger.warning("Failed to cache archive (too large or cache full)",
                 archive=archive_name,
                 items_count=len(all_items))
Cache Behavior:
  • First browse: Fetches from Borg (slow)
  • Subsequent browses: Uses Redis cache (600x faster)
  • Auto-invalidation: Cache cleared when archives change
  • Size limits: Enforced by cache service

Performance Tips

  • Redis Caching: Enable Redis for 600x faster archive browsing
  • Memory Limits: Adjust browse_max_items for very large archives
  • Directory Sizes: Calculated recursively from cached data
  • Bypass Lock: Use for read-only access to locked repositories
  • File Restoration: Extract only needed files, not entire archives
  • Cleanup: Use borg prune instead of manual archive deletion

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Bypass Lock Mode

Browse archives while backups are running: 
# From browse.py:59
bypass_lock=repository.bypass_lock
Use Cases:
  • Repository is locked by another operation
  • Read-only access to remote repositories
  • Observability-only repositories
Bypass lock mode uses borg --bypass-lock flag which is safe for read-only operations but should not be used during write operations.

​
File Listing Format

Borg UI parses JSON-lines output from Borg: 
{"path": "var/www/index.php", "type": "f", "size": 2048, "mtime": "2026-02-28T09:15:00"}
{"path": "var/www/html", "type": "d", "size": 0, "mtime": "2026-02-28T10:25:00"}
{"path": "var/www/html/image.jpg", "type": "f", "size": 524288, "mtime": "2026-02-27T14:30:00"}
Field Types:
  • f: Regular file
  • d: Directory
  • l: Symbolic link
  • h: Hard link

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