diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java
index defc4a4b..17b67960 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java
@@ -3,12 +3,14 @@ package org.qortal.arbitrary;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.crypto.Crypto;
+import org.qortal.settings.Settings;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.*;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
+import java.util.UUID;
 
 public class ArbitraryDataDiff {
 
@@ -17,6 +19,7 @@ public class ArbitraryDataDiff {
     private Path pathBefore;
     private Path pathAfter;
     private Path diffPath;
+    private String identifier;
 
     public ArbitraryDataDiff(Path pathBefore, Path pathAfter) {
         this.pathBefore = pathBefore;
@@ -35,6 +38,7 @@ public class ArbitraryDataDiff {
     }
 
     private void preExecute() {
+        this.createRandomIdentifier();
         this.createOutputDirectory();
     }
 
@@ -42,11 +46,16 @@ public class ArbitraryDataDiff {
 
     }
 
+    private void createRandomIdentifier() {
+        this.identifier = UUID.randomUUID().toString();
+    }
+
     private void createOutputDirectory() {
-        // Ensure temp folder exists
-        Path tempDir;
+        // Use the user-specified temp dir, as it is deterministic, and is more likely to be located on reusable storage hardware
+        String baseDir = Settings.getInstance().getTempDataPath();
+        Path tempDir = Paths.get(baseDir, "diff", this.identifier);
         try {
-            tempDir = Files.createTempDirectory("qortal-diff");
+            Files.createDirectories(tempDir);
         } catch (IOException e) {
             throw new IllegalStateException("Unable to create temp directory");
         }
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataFile.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataFile.java
index 4b91219e..9bb6fae9 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataFile.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataFile.java
@@ -255,13 +255,15 @@ public class ArbitraryDataFile {
         if (this.chunks != null && this.chunks.size() > 0) {
 
             // Create temporary path for joined file
-            Path tempPath;
+            // Use the user-specified temp dir, as it is deterministic, and is more likely to be located on reusable storage hardware
+            String baseDir = Settings.getInstance().getTempDataPath();
+            Path tempDir = Paths.get(baseDir, "join", this.chunks.get(0).digest58());
             try {
-                tempPath = Files.createTempFile(this.chunks.get(0).digest58(), ".tmp");
+                Files.createDirectories(tempDir);
             } catch (IOException e) {
                 return false;
             }
-            this.filePath = tempPath.toString();
+            this.filePath = tempDir.toString();
 
             // Join the chunks
             File outputFile = new File(this.filePath);
@@ -279,8 +281,8 @@ public class ArbitraryDataFile {
                 out.close();
 
                 // Copy temporary file to data directory
-                this.filePath = this.copyToDataDirectory(tempPath);
-                Files.delete(tempPath);
+                this.filePath = this.copyToDataDirectory(tempDir);
+                Files.delete(tempDir);
 
                 return true;
             } catch (FileNotFoundException e) {
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java
index f1163da4..8ac19db5 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java
@@ -4,6 +4,7 @@ import org.apache.commons.io.FileUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.crypto.Crypto;
+import org.qortal.settings.Settings;
 import org.qortal.utils.FilesystemUtils;
 
 import java.io.File;
@@ -11,6 +12,7 @@ import java.io.IOException;
 import java.nio.file.*;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
+import java.util.UUID;
 
 public class ArbitraryDataMerge {
 
@@ -19,6 +21,7 @@ public class ArbitraryDataMerge {
     private Path pathBefore;
     private Path pathAfter;
     private Path mergePath;
+    private String identifier;
 
     public ArbitraryDataMerge(Path pathBefore, Path pathAfter) {
         this.pathBefore = pathBefore;
@@ -37,6 +40,7 @@ public class ArbitraryDataMerge {
     }
 
     private void preExecute() {
+        this.createRandomIdentifier();
         this.createOutputDirectory();
     }
 
@@ -44,11 +48,16 @@ public class ArbitraryDataMerge {
 
     }
 
+    private void createRandomIdentifier() {
+        this.identifier = UUID.randomUUID().toString();
+    }
+
     private void createOutputDirectory() {
-        // Ensure temp folder exists
-        Path tempDir;
+        // Use the user-specified temp dir, as it is deterministic, and is more likely to be located on reusable storage hardware
+        String baseDir = Settings.getInstance().getTempDataPath();
+        Path tempDir = Paths.get(baseDir, "merge", this.identifier);
         try {
-            tempDir = Files.createTempDirectory("qortal-diff");
+            Files.createDirectories(tempDir);
         } catch (IOException e) {
             throw new IllegalStateException("Unable to create temp directory");
         }
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java
index 219d2293..4cf2486e 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java
@@ -9,6 +9,7 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.arbitrary.ArbitraryDataFile.*;
+import org.qortal.settings.Settings;
 import org.qortal.transform.Transformer;
 import org.qortal.utils.Base58;
 import org.qortal.utils.FilesystemUtils;
@@ -81,9 +82,9 @@ public class ArbitraryDataReader {
     }
 
     private void createWorkingDirectory() {
-        // Use the system tmpdir as our base, as it is deterministic
-        String baseDir = System.getProperty("java.io.tmpdir");
-        Path tempDir = Paths.get(baseDir + File.separator  + "qortal" + File.separator + this.resourceId);
+        // Use the user-specified temp dir, as it is deterministic, and is more likely to be located on reusable storage hardware
+        String baseDir = Settings.getInstance().getTempDataPath();
+        Path tempDir = Paths.get(baseDir, "reader", this.resourceId);
         try {
             Files.createDirectories(tempDir);
         } catch (IOException e) {
@@ -93,7 +94,6 @@ public class ArbitraryDataReader {
     }
 
     private void createUncompressedDirectory() {
-        // Use the system tmpdir as our base, as it is deterministic
         this.uncompressedPath = Paths.get(this.workingPath.toString() + File.separator + "data");
         try {
             Files.createDirectories(this.uncompressedPath);
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java
index 5d987b8d..d87256d0 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java
@@ -3,10 +3,13 @@ package org.qortal.arbitrary;
 import org.apache.commons.io.FileUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.qortal.crypto.Crypto;
 import org.qortal.data.transaction.ArbitraryTransactionData.*;
 import org.qortal.crypto.AES;
 import org.qortal.repository.DataException;
 import org.qortal.arbitrary.ArbitraryDataFile.*;
+import org.qortal.settings.Settings;
+import org.qortal.utils.Base58;
 import org.qortal.utils.ZipUtils;
 
 import javax.crypto.BadPaddingException;
@@ -78,10 +81,12 @@ public class ArbitraryDataWriter {
     }
 
     private void createWorkingDirectory() {
-        // Ensure temp folder exists
-        Path tempDir;
+        // Use the user-specified temp dir, as it is deterministic, and is more likely to be located on reusable storage hardware
+        String baseDir = Settings.getInstance().getTempDataPath();
+        String identifier = Crypto.digest(this.filePath.toString().getBytes()).toString();
+        Path tempDir = Paths.get(baseDir, "writer", identifier);
         try {
-            tempDir = Files.createTempDirectory("qortal");
+            Files.createDirectories(tempDir);
         } catch (IOException e) {
             throw new IllegalStateException("Unable to create temp directory");
         }
diff --git a/src/main/java/org/qortal/settings/Settings.java b/src/main/java/org/qortal/settings/Settings.java
index 7cd0f941..49a8a42c 100644
--- a/src/main/java/org/qortal/settings/Settings.java
+++ b/src/main/java/org/qortal/settings/Settings.java
@@ -206,6 +206,8 @@ public class Settings {
 
 	/** Data storage path. */
 	private String dataPath = "data";
+	/** Data storage path (for temporary data). */
+	private String tempDataPath = "data/_temp";
 
 
 	// Domain mapping
@@ -627,4 +629,8 @@ public class Settings {
 	public String getDataPath() {
 		return this.dataPath;
 	}
+
+	public String getTempDataPath() {
+		return this.tempDataPath;
+	}
 }