diff --git a/src/backups.js b/src/backups.js
index 9b31a1386..6464ad84d 100644
--- a/src/backups.js
+++ b/src/backups.js
@@ -379,6 +379,8 @@ function download(backupId, format, dataDir, callback) {
     assert.strictEqual(typeof dataDir, 'string');
     assert.strictEqual(typeof callback, 'function');
 
+    safe.fs.unlinkSync(paths.BACKUP_LOG_FILE); // start fresh log file
+
     log(`Downloading ${backupId} of format ${format} to ${dataDir}`);
 
     settings.getBackupConfig(function (error, backupConfig) {
@@ -436,7 +438,8 @@ function runBackupTask(backupId, format, dataDir, callback) {
 
     var killTimerId = null, progressTimerId = null;
 
-    var cp = shell.sudo(`backup-${backupId}`, [ BACKUPTASK_CMD, backupId, format, dataDir ], { env: process.env, logFile: paths.BACKUP_LOG_FILE }, function (error) {
+    var logStream = fs.createWriteStream(paths.BACKUP_LOG_FILE, { flags: 'a' });
+    var cp = shell.sudo(`backup-${backupId}`, [ BACKUPTASK_CMD, backupId, format, dataDir ], { env: process.env, logStream: logStream }, function (error) {
         clearTimeout(killTimerId);
         clearInterval(progressTimerId);
 
@@ -461,6 +464,11 @@ function runBackupTask(backupId, format, dataDir, callback) {
         debug('runBackupTask: backup task taking too long. killing');
         cp.kill();
     }, 4 * 60 * 60 * 1000); // 4 hours
+
+    logStream.on('error', function (error) {
+        debug('runBackupTask: error in logging stream', error);
+        cp.kill();
+    });
 }
 
 function getSnapshotInfo(id) {
diff --git a/src/shell.js b/src/shell.js
index 94827c886..5d94d799b 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -42,10 +42,9 @@ function exec(tag, file, args, options, callback) {
     debug(tag + ' execFile: %s', file); // do not dump args as it might have sensitive info
 
     var cp = child_process.spawn(file, args, options);
-    if (options.logFile) {
-        var logFile = fs.createWriteStream(options.logFile, { flags: 'a' });
-        cp.stdout.pipe(logFile);
-        cp.stderr.pipe(logFile);
+    if (options.logStream) {
+        cp.stdout.pipe(options.logStream);
+        cp.stderr.pipe(options.logStream);
     } else {
         cp.stdout.on('data', function (data) {
             debug(tag + ' (stdout): %s', data.toString('utf8'));
diff --git a/src/storage/filesystem.js b/src/storage/filesystem.js
index ade73ded0..9ba9f75f0 100644
--- a/src/storage/filesystem.js
+++ b/src/storage/filesystem.js
@@ -76,7 +76,7 @@ function download(apiConfig, sourceFilePath, callback) {
     callback(null, fileStream);
 }
 
-function downloadDir(apiConfig, backupFilePath, destDir, callback) {
+function downloadDir(apiConfig, backupFilePath, destDir) {
     assert.strictEqual(typeof apiConfig, 'object');
     assert.strictEqual(typeof backupFilePath, 'string');
     assert.strictEqual(typeof destDir, 'string');