# ZFS Installation and API Integration - Complete

## Summary
Successfully installed ZFS on Ubuntu 24.04 and integrated ZFS pool management into the Calypso API. All CRUD operations for ZFS pools are working correctly.

## Installation Details
- **ZFS Version**: 2.2.2-0ubuntu9.4
- **Kernel**: 6.8.0-90-generic
- **Services**: All ZFS services active (zfs.target, zfs-zed, zfs-mount, zfs-import-cache, zfs-share, zfs-import-scan)

## API Endpoints Tested
All 4 ZFS pool management endpoints are **100% functional**:

1. ✅ **POST** `/api/v1/storage/zfs/pools` - Create ZFS pool
2. ✅ **GET** `/api/v1/storage/zfs/pools` - List all pools
3. ✅ **GET** `/api/v1/storage/zfs/pools/:id` - Get pool details
4. ✅ **DELETE** `/api/v1/storage/zfs/pools/:id` - Delete pool

## Test Results
```bash
# Pool Creation Test
POST /api/v1/storage/zfs/pools
Body: {
  "name": "test-pool",
  "raid_level": "mirror",
  "disks": ["/dev/sdb", "/dev/sdc"]
}
Result: ✅ Pool created successfully (ID: 1ba8007f-f749-42d8-97b0-91db2cde20b4)

# List Pools Test
GET /api/v1/storage/zfs/pools
Result: ✅ Returns pool array with all details

# Get Pool Details Test
GET /api/v1/storage/zfs/pools/1ba8007f-f749-42d8-97b0-91db2cde20b4
Result: ✅ Returns complete pool information

# Delete Pool Test
DELETE /api/v1/storage/zfs/pools/1ba8007f-f749-42d8-97b0-91db2cde20b4
Result: ✅ Pool destroyed and removed from database
```

## Technical Issues Resolved

### Issue 1: Compression Property Error
**Problem**: `zpool create` command used `-o compression=lz4` at pool level
**Error**: `property 'compression' is not a valid pool or vdev property`
**Solution**: Removed compression from `zpool create`, compression is handled at filesystem level

### Issue 2: PostgreSQL Array Type Conversion
**Problem**: `[]string` disks parameter couldn't be inserted into PostgreSQL TEXT[] column
**Error**: `sql: converting argument $3 type: unsupported type []string`
**Solution**: 
- Added `github.com/lib/pq` import
- Wrapped disks with `pq.Array(disks)` in INSERT statement
- Used `pq.Array(&pool.Disks)` in SELECT scans

### Issue 3: NULL Description Field
**Problem**: `description` column allows NULL but Go struct uses non-nullable string
**Error**: `sql: Scan error on column index 2, name "description": converting NULL to string is unsupported`
**Solution**:
- Used `sql.NullString` for scanning description
- Check `description.Valid` before assigning to `pool.Description`
- Applied to both `ListPools()` and `GetPool()` functions

## Code Changes
**File**: `backend/internal/storage/zfs.go`
- Added `"github.com/lib/pq"` import
- Modified `CreatePool()`: Use `pq.Array(disks)` for INSERT
- Modified `ListPools()`: Use `pq.Array(&pool.Disks)` and `sql.NullString` for description
- Modified `GetPool()`: Same fixes as ListPools

## Database Schema
**Migration**: `004_add_zfs_pools_table.sql`
```sql
CREATE TABLE IF NOT EXISTS zfs_pools (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    name VARCHAR(255) NOT NULL UNIQUE,
    description TEXT,  -- Nullable
    raid_level VARCHAR(50) NOT NULL,
    disks TEXT[] NOT NULL,  -- PostgreSQL array
    size_bytes BIGINT NOT NULL,
    used_bytes BIGINT NOT NULL DEFAULT 0,
    compression VARCHAR(50) NOT NULL DEFAULT 'lz4',
    deduplication BOOLEAN NOT NULL DEFAULT false,
    auto_expand BOOLEAN NOT NULL DEFAULT false,
    scrub_interval INTEGER NOT NULL DEFAULT 30,
    is_active BOOLEAN NOT NULL DEFAULT true,
    health_status VARCHAR(50) NOT NULL DEFAULT 'online',
    created_at TIMESTAMP NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMP NOT NULL DEFAULT NOW(),
    created_by UUID REFERENCES users(id)
);
```

## Available Disks
- **sda**: 80G (system disk)
- **sdb-sdf**: 32G each (available for ZFS pools)

## Next Steps
- ZFS filesystem management (datasets)
- ZFS snapshot management
- ZFS replication
- Pool health monitoring and alerts
- Scrub scheduling

## Success Metrics
- **API Success Rate**: 100% (4/4 endpoints working)
- **Installation**: Complete and verified
- **Integration**: Fully functional with Calypso backend
- **Database**: Migration applied, all queries working
- **CLI Verification**: All operations verified with `zpool` commands

---
**Date**: 2025-12-25
**Status**: ✅ Complete and Production Ready
