Implement enhanced storage pool visualization

- Add support for mergerfs pool grouping with data and parity disk separation
- Implement pool health monitoring (healthy/degraded/critical status)
- Create hierarchical tree view for multi-disk storage arrays
- Add automatic pool type detection and member disk association
- Maintain backward compatibility for single disk configurations
- Support future extension for RAID and ZFS pool types

agent/src/collectors/disk.rs

@@ -15,12 +15,45 @@ struct StoragePool {
     name: String,            // e.g., "steampool", "root"
     mount_point: String,     // e.g., "/mnt/steampool", "/"
     filesystem: String,      // e.g., "mergerfs", "ext4", "zfs", "btrfs"
-    storage_type: String,    // e.g., "mergerfs", "single", "raid", "zfs"
+    pool_type: StoragePoolType, // Enhanced pool type with configuration
     size: String,            // e.g., "2.5TB"
     used: String,            // e.g., "2.1TB"
     available: String,       // e.g., "400GB"
     usage_percent: f32,      // e.g., 85.0
     underlying_drives: Vec<DriveInfo>, // Individual physical drives
+    pool_health: PoolHealth, // Overall pool health status
+}
+
+/// Enhanced storage pool types with specific configurations
+#[derive(Debug, Clone)]
+enum StoragePoolType {
+    Single,                    // Traditional single disk
+    MergerfsPool {            // MergerFS with optional parity
+        data_disks: Vec<String>,      // Member disk names (sdb, sdd)
+        parity_disks: Vec<String>,    // Parity disk names (sdc)
+    },
+    #[allow(dead_code)]
+    RaidArray {               // Hardware RAID (future)
+        level: String,               // "RAID1", "RAID5", etc.
+        member_disks: Vec<String>,   
+        spare_disks: Vec<String>,
+    },
+    #[allow(dead_code)]
+    ZfsPool {                 // ZFS pool (future)
+        pool_name: String,
+        vdevs: Vec<String>,
+    }
+}
+
+/// Pool health status for redundant storage
+#[derive(Debug, Clone, Copy, PartialEq)]
+enum PoolHealth {
+    Healthy,           // All drives OK, parity current
+    Degraded,          // One drive failed or parity outdated, still functional
+    Critical,          // Multiple failures, data at risk
+    #[allow(dead_code)]
+    Rebuilding,        // Actively rebuilding/scrubbing (future: SnapRAID status integration)
+    Unknown,           // Cannot determine status
 }
 
 /// Information about an individual physical drive
@@ -75,12 +108,39 @@ impl DiskCollector {
     /// Get configured storage pools with individual drive information
     fn get_configured_storage_pools(&self) -> Result<Vec<StoragePool>> {
         let mut storage_pools = Vec::new();
+        let mut processed_pools = std::collections::HashSet::new();
 
+        // First pass: Create enhanced pools (mergerfs, etc.)
         for fs_config in &self.config.filesystems {
             if !fs_config.monitor {
                 continue;
             }
 
+            let (pool_type, skip_in_single_mode) = self.determine_pool_type(&fs_config.storage_type);
+            
+            // Skip member disks if they're part of a pool
+            if skip_in_single_mode {
+                continue;
+            }
+
+            // Check if this pool was already processed (in case of multiple member disks)
+            let pool_key = match &pool_type {
+                StoragePoolType::MergerfsPool { .. } => {
+                    // For mergerfs pools, use the main mount point
+                    if fs_config.fs_type == "fuse.mergerfs" {
+                        fs_config.mount_point.clone()
+                    } else {
+                        continue; // Skip member disks
+                    }
+                }
+                _ => fs_config.mount_point.clone()
+            };
+
+            if processed_pools.contains(&pool_key) {
+                continue;
+            }
+            processed_pools.insert(pool_key.clone());
+
             // Get filesystem stats for the mount point
             match self.get_filesystem_info(&fs_config.mount_point) {
                 Ok((total_bytes, used_bytes)) => {
@@ -96,25 +156,29 @@ impl DiskCollector {
                     let used = self.bytes_to_human_readable(used_bytes);
                     let available = self.bytes_to_human_readable(available_bytes);
 
-                    // Get individual drive information using pre-detected devices
-                    let device_names = self.detected_devices.get(&fs_config.mount_point).cloned().unwrap_or_default();
-                    let underlying_drives = self.get_drive_info_for_devices(&device_names)?;
+                    // Get underlying drives based on pool type
+                    let underlying_drives = self.get_pool_drives(&pool_type, &fs_config.mount_point)?;
+                    
+                    // Calculate pool health
+                    let pool_health = self.calculate_pool_health(&pool_type, &underlying_drives);
+                    let drive_count = underlying_drives.len();
 
                     storage_pools.push(StoragePool {
                         name: fs_config.name.clone(),
                         mount_point: fs_config.mount_point.clone(),
                         filesystem: fs_config.fs_type.clone(),
-                        storage_type: fs_config.storage_type.clone(),
+                        pool_type: pool_type.clone(),
                         size,
                         used,
                         available,
                         usage_percent: usage_percent as f32,
                         underlying_drives,
+                        pool_health,
                     });
 
                     debug!(
-                        "Storage pool '{}' ({}) at {} with {} detected drives",
-                        fs_config.name, fs_config.storage_type, fs_config.mount_point, device_names.len()
+                        "Storage pool '{}' ({:?}) at {} with {} drives, health: {:?}",
+                        fs_config.name, pool_type, fs_config.mount_point, drive_count, pool_health
                     );
                 }
                 Err(e) => {
@@ -129,6 +193,123 @@ impl DiskCollector {
         Ok(storage_pools)
     }
 
+    /// Determine the storage pool type from configuration
+    fn determine_pool_type(&self, storage_type: &str) -> (StoragePoolType, bool) {
+        match storage_type {
+            "single" => (StoragePoolType::Single, false),
+            "mergerfs_pool" | "mergerfs" => {
+                // Find associated member disks
+                let data_disks = self.find_pool_member_disks("mergerfs_member");
+                let parity_disks = self.find_pool_member_disks("parity");
+                (StoragePoolType::MergerfsPool { data_disks, parity_disks }, false)
+            }
+            "mergerfs_member" => (StoragePoolType::Single, true), // Skip, part of pool
+            "parity" => (StoragePoolType::Single, true), // Skip, part of pool  
+            "raid1" | "raid5" | "raid6" => {
+                let member_disks = self.find_pool_member_disks(&format!("{}_member", storage_type));
+                (StoragePoolType::RaidArray { 
+                    level: storage_type.to_uppercase(), 
+                    member_disks, 
+                    spare_disks: Vec::new() 
+                }, false)
+            }
+            _ => (StoragePoolType::Single, false) // Default to single
+        }
+    }
+
+    /// Find member disks for a specific storage type
+    fn find_pool_member_disks(&self, member_type: &str) -> Vec<String> {
+        let mut member_disks = Vec::new();
+        
+        for fs_config in &self.config.filesystems {
+            if fs_config.storage_type == member_type && fs_config.monitor {
+                // Get device names for this mount point
+                if let Some(devices) = self.detected_devices.get(&fs_config.mount_point) {
+                    member_disks.extend(devices.clone());
+                }
+            }
+        }
+        
+        member_disks
+    }
+
+    /// Get drive information for a specific pool type
+    fn get_pool_drives(&self, pool_type: &StoragePoolType, mount_point: &str) -> Result<Vec<DriveInfo>> {
+        match pool_type {
+            StoragePoolType::Single => {
+                // Single disk - use detected devices for this mount point
+                let device_names = self.detected_devices.get(mount_point).cloned().unwrap_or_default();
+                self.get_drive_info_for_devices(&device_names)
+            }
+            StoragePoolType::MergerfsPool { data_disks, parity_disks } => {
+                // Mergerfs pool - collect all member drives
+                let mut all_disks = data_disks.clone();
+                all_disks.extend(parity_disks.clone());
+                self.get_drive_info_for_devices(&all_disks)
+            }
+            StoragePoolType::RaidArray { member_disks, spare_disks, .. } => {
+                // RAID array - collect member and spare drives
+                let mut all_disks = member_disks.clone();
+                all_disks.extend(spare_disks.clone());
+                self.get_drive_info_for_devices(&all_disks)
+            }
+            StoragePoolType::ZfsPool { .. } => {
+                // ZFS pool - use detected devices (future implementation)
+                let device_names = self.detected_devices.get(mount_point).cloned().unwrap_or_default();
+                self.get_drive_info_for_devices(&device_names)
+            }
+        }
+    }
+
+    /// Calculate pool health based on drive status and pool type
+    fn calculate_pool_health(&self, pool_type: &StoragePoolType, drives: &[DriveInfo]) -> PoolHealth {
+        match pool_type {
+            StoragePoolType::Single => {
+                // Single disk - health is just the drive health
+                if drives.is_empty() {
+                    PoolHealth::Unknown
+                } else if drives.iter().all(|d| d.health_status == "PASSED") {
+                    PoolHealth::Healthy
+                } else {
+                    PoolHealth::Critical
+                }
+            }
+            StoragePoolType::MergerfsPool { data_disks, parity_disks } => {
+                let failed_data = drives.iter()
+                    .filter(|d| data_disks.contains(&d.device) && d.health_status != "PASSED")
+                    .count();
+                let failed_parity = drives.iter()
+                    .filter(|d| parity_disks.contains(&d.device) && d.health_status != "PASSED")
+                    .count();
+                
+                match (failed_data, failed_parity) {
+                    (0, 0) => PoolHealth::Healthy,
+                    (1, 0) => PoolHealth::Degraded,  // Can recover with parity
+                    (0, 1) => PoolHealth::Degraded,  // Lost parity protection
+                    _ => PoolHealth::Critical,       // Multiple failures
+                }
+            }
+            StoragePoolType::RaidArray { level, .. } => {
+                let failed_drives = drives.iter().filter(|d| d.health_status != "PASSED").count();
+                
+                // Basic RAID health logic (can be enhanced per RAID level)
+                match failed_drives {
+                    0 => PoolHealth::Healthy,
+                    1 if level.contains('1') || level.contains('5') || level.contains('6') => PoolHealth::Degraded,
+                    _ => PoolHealth::Critical,
+                }
+            }
+            StoragePoolType::ZfsPool { .. } => {
+                // ZFS health would require zpool status parsing (future)
+                if drives.iter().all(|d| d.health_status == "PASSED") {
+                    PoolHealth::Healthy
+                } else {
+                    PoolHealth::Degraded
+                }
+            }
+        }
+    }
+
     /// Get drive information for a list of device names
     fn get_drive_info_for_devices(&self, device_names: &[String]) -> Result<Vec<DriveInfo>> {
         let mut drives = Vec::new();
@@ -448,8 +629,8 @@ impl Collector for DiskCollector {
             let used_gb = self.parse_size_to_gb(&storage_pool.used);
             let avail_gb = self.parse_size_to_gb(&storage_pool.available);
 
-            // Calculate status based on configured thresholds
-            let pool_status = if storage_pool.usage_percent >= self.config.usage_critical_percent {
+            // Calculate status based on configured thresholds and pool health
+            let usage_status = if storage_pool.usage_percent >= self.config.usage_critical_percent {
                 Status::Critical
             } else if storage_pool.usage_percent >= self.config.usage_warning_percent {
                 Status::Warning
@@ -457,6 +638,14 @@ impl Collector for DiskCollector {
                 Status::Ok
             };
 
+            let pool_status = match storage_pool.pool_health {
+                PoolHealth::Critical => Status::Critical,
+                PoolHealth::Degraded => Status::Warning,
+                PoolHealth::Rebuilding => Status::Warning,
+                PoolHealth::Healthy => usage_status,
+                PoolHealth::Unknown => Status::Unknown,
+            };
+
             // Storage pool info metrics
             metrics.push(Metric {
                 name: format!("disk_{}_mount_point", pool_name),
@@ -476,15 +665,47 @@ impl Collector for DiskCollector {
                 timestamp,
             });
 
+            // Enhanced pool type information
+            let pool_type_str = match &storage_pool.pool_type {
+                StoragePoolType::Single => "single".to_string(),
+                StoragePoolType::MergerfsPool { data_disks, parity_disks } => {
+                    format!("mergerfs ({}+{})", data_disks.len(), parity_disks.len())
+                }
+                StoragePoolType::RaidArray { level, member_disks, spare_disks } => {
+                    format!("{} ({}+{})", level, member_disks.len(), spare_disks.len())
+                }
+                StoragePoolType::ZfsPool { pool_name, .. } => {
+                    format!("zfs ({})", pool_name)
+                }
+            };
+
             metrics.push(Metric {
-                name: format!("disk_{}_storage_type", pool_name),
-                value: MetricValue::String(storage_pool.storage_type.clone()),
+                name: format!("disk_{}_pool_type", pool_name),
+                value: MetricValue::String(pool_type_str.clone()),
                 unit: None,
-                description: Some(format!("Type: {}", storage_pool.storage_type)),
+                description: Some(format!("Type: {}", pool_type_str)),
                 status: Status::Ok,
                 timestamp,
             });
 
+            // Pool health status
+            let health_str = match storage_pool.pool_health {
+                PoolHealth::Healthy => "healthy",
+                PoolHealth::Degraded => "degraded", 
+                PoolHealth::Critical => "critical",
+                PoolHealth::Rebuilding => "rebuilding",
+                PoolHealth::Unknown => "unknown",
+            };
+
+            metrics.push(Metric {
+                name: format!("disk_{}_pool_health", pool_name),
+                value: MetricValue::String(health_str.to_string()),
+                unit: None,
+                description: Some(format!("Health: {}", health_str)),
+                status: pool_status,
+                timestamp,
+            });
+
             // Storage pool size metrics
             metrics.push(Metric {
                 name: format!("disk_{}_total_gb", pool_name),