Enrich database_size_stats with drive-level volume space

Lite/Database/DuckDbInitializer.cs

@@ -86,7 +86,7 @@ public void Dispose()
     /// <summary>
     /// Current schema version. Increment this when schema changes require table rebuilds.
     /// </summary>
-    internal const int CurrentSchemaVersion = 16;
+    internal const int CurrentSchemaVersion = 17;
 
     private readonly string _archivePath;
 
@@ -505,6 +505,23 @@ New tables only — no existing table changes needed. Tables created by
                     GetAllTableStatements() during initialization. */
             _logger?.LogInformation("Running migration to v16: adding FinOps tables (database_size_stats, server_properties)");
         }
+
+        if (fromVersion < 17)
+        {
+            /* v17: Added volume-level drive space columns to database_size_stats.
+                    Columns appended at end — safe for DuckDB appender positional writes. */
+            _logger?.LogInformation("Running migration to v17: adding volume stats columns to database_size_stats");
+            try
+            {
+                await ExecuteNonQueryAsync(connection, "ALTER TABLE database_size_stats ADD COLUMN IF NOT EXISTS volume_mount_point VARCHAR");
+                await ExecuteNonQueryAsync(connection, "ALTER TABLE database_size_stats ADD COLUMN IF NOT EXISTS volume_total_mb DECIMAL(19,2)");
+                await ExecuteNonQueryAsync(connection, "ALTER TABLE database_size_stats ADD COLUMN IF NOT EXISTS volume_free_mb DECIMAL(19,2)");
+            }
+            catch
+            {
+                /* Table doesn't exist yet — will be created with correct schema below */
+            }
+        }
     }
 
     /// <summary>

Lite/Database/Schema.cs

@@ -609,7 +609,10 @@ auto_growth_mb DECIMAL(19,2),
     max_size_mb DECIMAL(19,2),
     recovery_model_desc VARCHAR,
     compatibility_level INTEGER,
-    state_desc VARCHAR
+    state_desc VARCHAR,
+    volume_mount_point VARCHAR,
+    volume_total_mb DECIMAL(19,2),
+    volume_free_mb DECIMAL(19,2)
 )";
 
     public const string CreateDatabaseSizeStatsIndex = @"

Lite/Services/RemoteCollectorService.DatabaseSize.cs

@@ -22,8 +22,8 @@ public partial class RemoteCollectorService
 {
     /// <summary>
     /// Collects per-file database sizes for growth trending and capacity planning.
-    /// On-prem: queries sys.master_files + sys.databases for all online databases.
-    /// Azure SQL DB: queries sys.database_files for the single database.
+    /// On-prem: queries sys.master_files + sys.databases + dm_os_volume_stats for file and drive context.
+    /// Azure SQL DB: queries sys.database_files for the single database (no volume stats available).
     /// </summary>
     private async Task<int> CollectDatabaseSizeStatsAsync(ServerConnection server, CancellationToken cancellationToken)
     {
@@ -63,10 +63,17 @@ ELSE CONVERT(decimal(19,2), mf.max_size * 8.0 / 1024.0)
     compatibility_level =
         CONVERT(int, d.compatibility_level),
     state_desc =
-        d.state_desc
+        d.state_desc,
+    volume_mount_point =
+        RTRIM(vs.volume_mount_point),
+    volume_total_mb =
+        CONVERT(decimal(19,2), vs.total_bytes / 1048576.0),
+    volume_free_mb =
+        CONVERT(decimal(19,2), vs.available_bytes / 1048576.0)
 FROM sys.master_files AS mf
 JOIN sys.databases AS d
   ON d.database_id = mf.database_id
+CROSS APPLY sys.dm_os_volume_stats(mf.database_id, mf.file_id) AS vs
 WHERE d.state_desc = N'ONLINE'
 ORDER BY
     d.name,
@@ -106,7 +113,13 @@ ELSE CONVERT(decimal(19,2), df.max_size * 8.0 / 1024.0)
     compatibility_level =
         CONVERT(int, NULL),
     state_desc =
-        N'ONLINE'
+        N'ONLINE',
+    volume_mount_point =
+        CONVERT(nvarchar(256), NULL),
+    volume_total_mb =
+        CONVERT(decimal(19,2), NULL),
+    volume_free_mb =
+        CONVERT(decimal(19,2), NULL)
 FROM sys.database_files AS df
 ORDER BY
     df.file_id
@@ -123,7 +136,8 @@ ORDER BY
         var rows = new List<(string DatabaseName, int DatabaseId, int FileId, string FileTypeDesc,
             string FileName, string PhysicalName, decimal TotalSizeMb, decimal? UsedSizeMb,
             decimal? AutoGrowthMb, decimal? MaxSizeMb, string? RecoveryModel,
-            int? CompatibilityLevel, string? StateDesc)>();
+            int? CompatibilityLevel, string? StateDesc, string? VolumeMountPoint,
+            decimal? VolumeTotalMb, decimal? VolumeFreeMb)>();
 
         var sqlSw = Stopwatch.StartNew();
         using var sqlConnection = await CreateConnectionAsync(server, cancellationToken);
@@ -146,7 +160,10 @@ ORDER BY
                 reader.IsDBNull(9) ? null : reader.GetDecimal(9),
                 reader.IsDBNull(10) ? null : reader.GetString(10),
                 reader.IsDBNull(11) ? null : reader.GetInt32(11),
-                reader.IsDBNull(12) ? null : reader.GetString(12)));
+                reader.IsDBNull(12) ? null : reader.GetString(12),
+                reader.IsDBNull(13) ? null : reader.GetString(13),
+                reader.IsDBNull(14) ? null : reader.GetDecimal(14),
+                reader.IsDBNull(15) ? null : reader.GetDecimal(15)));
         }
         sqlSw.Stop();
 
@@ -178,6 +195,9 @@ ORDER BY
                        .AppendValue(r.RecoveryModel)
                        .AppendValue(r.CompatibilityLevel)
                        .AppendValue(r.StateDesc)
+                       .AppendValue(r.VolumeMountPoint)
+                       .AppendValue(r.VolumeTotalMb)
+                       .AppendValue(r.VolumeFreeMb)
                        .EndRow();
                     rowsCollected++;
                 }

install/02_create_tables.sql

@@ -1430,6 +1430,9 @@ BEGIN
         recovery_model_desc nvarchar(12) NULL,
         compatibility_level integer NULL,
         state_desc nvarchar(60) NULL,
+        volume_mount_point nvarchar(256) NULL,
+        volume_total_mb decimal(19,2) NULL,
+        volume_free_mb decimal(19,2) NULL,
         /*Analysis helpers - computed columns*/
         free_space_mb AS
         (

install/06_ensure_collection_table.sql

@@ -1110,6 +1110,9 @@ BEGIN
                 recovery_model_desc nvarchar(12) NULL,
                 compatibility_level integer NULL,
                 state_desc nvarchar(60) NULL,
+                volume_mount_point nvarchar(256) NULL,
+                volume_total_mb decimal(19,2) NULL,
+                volume_free_mb decimal(19,2) NULL,
                 free_space_mb AS
                 (
                     total_size_mb - used_size_mb

install/52_collect_database_size_stats.sql

@@ -112,7 +112,10 @@ BEGIN
                 max_size_mb,
                 recovery_model_desc,
                 compatibility_level,
-                state_desc
+                state_desc,
+                volume_mount_point,
+                volume_total_mb,
+                volume_free_mb
             )
             SELECT
                 collection_time = @start_time,
@@ -147,7 +150,10 @@ BEGIN
                 recovery_model_desc =
                     CONVERT(nvarchar(12), DATABASEPROPERTYEX(DB_NAME(), N'Recovery')),
                 compatibility_level = NULL,
-                state_desc = N'ONLINE'
+                state_desc = N'ONLINE',
+                volume_mount_point = NULL,
+                volume_total_mb = NULL,
+                volume_free_mb = NULL
             FROM sys.database_files AS df
             OPTION(RECOMPILE);
 
@@ -200,7 +206,10 @@ BEGIN
                         max_size_mb,
                         recovery_model_desc,
                         compatibility_level,
-                        state_desc
+                        state_desc,
+                        volume_mount_point,
+                        volume_total_mb,
+                        volume_free_mb
                     )
                     SELECT
                         collection_time = @start_time,
@@ -234,9 +243,16 @@ BEGIN
                             END,
                         recovery_model_desc = d.recovery_model_desc,
                         compatibility_level = d.compatibility_level,
-                        state_desc = d.state_desc
+                        state_desc = d.state_desc,
+                        volume_mount_point =
+                            RTRIM(vs.volume_mount_point),
+                        volume_total_mb =
+                            CONVERT(decimal(19,2), vs.total_bytes / 1048576.0),
+                        volume_free_mb =
+                            CONVERT(decimal(19,2), vs.available_bytes / 1048576.0)
                     FROM sys.database_files AS df
                     CROSS JOIN sys.databases AS d
+                    CROSS APPLY sys.dm_os_volume_stats(DB_ID(), df.file_id) AS vs
                     WHERE d.database_id = DB_ID();';
 
                     EXECUTE sys.sp_executesql
@@ -277,7 +293,10 @@ BEGIN
                 dss.total_size_mb,
                 dss.used_size_mb,
                 dss.free_space_mb,
-                dss.used_pct
+                dss.used_pct,
+                dss.volume_mount_point,
+                dss.volume_total_mb,
+                dss.volume_free_mb
             FROM collect.database_size_stats AS dss
             WHERE dss.collection_time = @start_time
             ORDER BY

upgrades/2.1.0-to-2.2.0/06_add_volume_stats_columns.sql

@@ -0,0 +1,41 @@
+/*
+Copyright 2026 Darling Data, LLC
+https://www.erikdarling.com/
+
+Upgrade from 2.1.0 to 2.2.0
+Adds volume-level drive space columns to database_size_stats.
+*/
+
+SET ANSI_NULLS ON;
+SET ANSI_PADDING ON;
+SET ANSI_WARNINGS ON;
+SET ARITHABORT ON;
+SET CONCAT_NULL_YIELDS_NULL ON;
+SET QUOTED_IDENTIFIER ON;
+SET NUMERIC_ROUNDABORT OFF;
+SET IMPLICIT_TRANSACTIONS OFF;
+SET STATISTICS TIME, IO OFF;
+GO
+
+USE PerformanceMonitor;
+GO
+
+IF NOT EXISTS
+(
+    SELECT
+        1/0
+    FROM sys.columns
+    WHERE object_id = OBJECT_ID(N'collect.database_size_stats', N'U')
+    AND   name = N'volume_mount_point'
+)
+BEGIN
+    ALTER TABLE
+        collect.database_size_stats
+    ADD
+        volume_mount_point nvarchar(256) NULL,
+        volume_total_mb decimal(19,2) NULL,
+        volume_free_mb decimal(19,2) NULL;
+
+    PRINT 'Added volume_mount_point, volume_total_mb, volume_free_mb to collect.database_size_stats';
+END;
+GO

upgrades/2.1.0-to-2.2.0/upgrade.txt

@@ -3,3 +3,4 @@
 03_compress_procedure_stats.sql
 04_create_tracking_tables.sql
 05_add_finops_collectors.sql
+06_add_volume_stats_columns.sql