diff --git a/core/tar-itop.class.inc.php b/core/tar-itop.class.inc.php
new file mode 100644
index 000000000..bf46a15d5
--- /dev/null
+++ b/core/tar-itop.class.inc.php
@@ -0,0 +1,130 @@
+<?php
+// Copyright (C) 2010-2018 Combodo SARL
+//
+//   This file is part of iTop.
+//
+//   iTop is free software; you can redistribute it and/or modify
+//   it under the terms of the GNU Affero General Public License as published by
+//   the Free Software Foundation, either version 3 of the License, or
+//   (at your option) any later version.
+//
+//   iTop is distributed in the hope that it will be useful,
+//   but WITHOUT ANY WARRANTY; without even the implied warranty of
+//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//   GNU Affero General Public License for more details.
+//
+//   You should have received a copy of the GNU Affero General Public License
+//   along with iTop. If not, see <http://www.gnu.org/licenses/>
+
+require_once(APPROOT.'lib/archivetar/tar.php');
+
+/**
+ * Class ITopArchiveTar
+ * Custom Combodo code added to the {@link ArchiveTar} class
+ */
+class ITopArchiveTar extends ArchiveTar
+{
+	/**
+	 * @param string $p_message
+	 */
+	public function _error($p_message)
+	{
+		IssueLog::Error($p_message);
+	}
+
+	/**
+	 * @param string $p_message
+	 */
+	public function _warning($p_message)
+	{
+		IssueLog::Warning($p_message);
+	}
+
+	/**
+	 * @param string $p_filename
+	 * @return bool
+	 */
+	public function _writeLongHeader($p_filename)
+	{
+		$v_uid = sprintf("%07s", 0);
+		$v_gid = sprintf("%07s", 0);
+		$v_perms = sprintf("%07s", 0);
+		$v_size = sprintf("%'011s", DecOct(strlen($p_filename)));
+		$v_mtime = sprintf("%011s", 0);
+		$v_typeflag = 'L';
+		$v_linkname = '';
+		$v_magic = 'ustar ';
+		$v_version = ' ';
+		$v_uname = '';
+		$v_gname = '';
+		$v_devmajor = '';
+		$v_devminor = '';
+		$v_prefix = '';
+		$v_binary_data_first = pack(
+			"a100a8a8a8a12a12",
+			'././@LongLink',
+			$v_perms,
+			$v_uid,
+			$v_gid,
+			$v_size,
+			$v_mtime
+		);
+		$v_binary_data_last = pack(
+			"a1a100a6a2a32a32a8a8a155a12",
+			$v_typeflag,
+			$v_linkname,
+			$v_magic,
+			$v_version,
+			$v_uname,
+			$v_gname,
+			$v_devmajor,
+			$v_devminor,
+			$v_prefix,
+			''
+		);
+
+		// ----- Calculate the checksum
+		$v_checksum = 0;
+		// ..... First part of the header
+		for ($i = 0; $i < 148; $i++) {
+			$v_checksum += ord(substr($v_binary_data_first, $i, 1));
+		}
+		// ..... Ignore the checksum value and replace it by ' ' (space)
+		for ($i = 148; $i < 156; $i++) {
+			$v_checksum += ord(' ');
+		}
+		// ..... Last part of the header
+		for ($i = 156, $j = 0; $i < 512; $i++, $j++) {
+			$v_checksum += ord(substr($v_binary_data_last, $j, 1));
+		}
+
+		// ----- Write the first 148 bytes of the header in the archive
+		$this->_writeBlock($v_binary_data_first, 148);
+
+		// ----- Write the calculated checksum
+		$v_checksum = sprintf("%06s ", DecOct($v_checksum));
+		$v_binary_data = pack("a8", $v_checksum);
+		$this->_writeBlock($v_binary_data, 8);
+
+		// ----- Write the last 356 bytes of the header in the archive
+		$this->_writeBlock($v_binary_data_last, 356);
+
+		// ----- Write the filename as content of the block
+		$i = 0;
+		while (($v_buffer = substr($p_filename, (($i++) * 512), 512)) != '') {
+			$v_binary_data = pack("a512", "$v_buffer");
+			$this->_writeBlock($v_binary_data);
+		}
+
+		return true;
+	}
+
+	// This is overloaded too but private...
+	// private function _maliciousFilename($file)
+
+	public function _addFile($p_filename, &$p_header, $p_add_dir, $p_remove_dir, $v_stored_filename = null)
+	{
+		// This method is modified, but cannot overload it here as it calls the \ArchiveTar::_pathReduction private method
+		return parent::_addFile($p_filename, $p_header, $p_add_dir, $p_remove_dir, $v_stored_filename);
+	}
+}
\ No newline at end of file
diff --git a/lib/archivetar/README.md b/lib/archivetar/README.md
new file mode 100644
index 000000000..cc80d64c3
--- /dev/null
+++ b/lib/archivetar/README.md
@@ -0,0 +1,10 @@
+https://github.com/combodo-itop-libs/Archive_Tar  
+Forked from https://github.com/pear/Archive_Tar
+
+Base version : a modified v1.4.4 (https://github.com/pear/Archive_Tar/blob/1.4.4/Archive/Tar.php)
+
+Combodo modifications are inside those comments :
+```php
+// --- START COMBODO modification
+// --- END COMBODO modification
+```
diff --git a/setup/tar.php b/lib/archivetar/tar.php
similarity index 99%
rename from setup/tar.php
rename to lib/archivetar/tar.php
index ac3e67f7e..050c22cfa 100644
--- a/setup/tar.php
+++ b/lib/archivetar/tar.php
@@ -680,7 +680,7 @@ class ArchiveTar
 	 */
 	public function _error($p_message)
 	{
-		IssueLog::Error($p_message);
+		$this->error_object = $this->raiseError($p_message);
 	}
 
 	/**
@@ -688,7 +688,7 @@ class ArchiveTar
 	 */
 	public function _warning($p_message)
 	{
-		IssueLog::Warning($p_message);
+		$this->error_object = $this->raiseError($p_message);
 	}
 
 	/**
@@ -1209,6 +1209,10 @@ class ArchiveTar
 				return false;
 			}
 
+			// --- START COMBODO modification
+			// (see commit 2706ebf6)
+			// read/write files with a bigger buffer to increase drastically performances
+			// to still get a valid archive, last bytes are still read/write using a 512 byte buffer
 			$iLen = 1024*1024;
 			while (($v_buffer = fread($v_file, $iLen)) != '') {
 				$iBufferLen = strlen("$v_buffer");
@@ -1224,6 +1228,7 @@ class ArchiveTar
 				$v_binary_data = pack($sPack, "$v_buffer");
 				$this->_writeBlock($v_binary_data);
 			}
+			// --- END COMBODO modification
 
 			fclose($v_file);
 		} else {
@@ -1518,28 +1523,34 @@ class ArchiveTar
 	 */
 	public function _writeLongHeader($p_filename)
 	{
-		$v_uid = sprintf("%07s", 0);
-		$v_gid = sprintf("%07s", 0);
-		$v_perms = sprintf("%07s", 0);
-		$v_size = sprintf("%'011s", DecOct(strlen($p_filename)));
-		$v_mtime = sprintf("%011s", 0);
+		$v_size = sprintf("%11s ", DecOct(strlen($p_filename)));
+
 		$v_typeflag = 'L';
+
 		$v_linkname = '';
-		$v_magic = 'ustar ';
-		$v_version = ' ';
+
+		$v_magic = '';
+
+		$v_version = '';
+
 		$v_uname = '';
+
 		$v_gname = '';
+
 		$v_devmajor = '';
+
 		$v_devminor = '';
+
 		$v_prefix = '';
+
 		$v_binary_data_first = pack(
 			"a100a8a8a8a12a12",
 			'././@LongLink',
-			$v_perms,
-			$v_uid,
-			$v_gid,
+			0,
+			0,
+			0,
 			$v_size,
-			$v_mtime
+			0
 		);
 		$v_binary_data_last = pack(
 			"a1a100a6a2a32a32a8a8a155a12",
@@ -1722,6 +1733,7 @@ class ArchiveTar
 		if (strpos($file, 'phar://') === 0) {
 			return true;
 		}
+
 		if (strpos($file, '/../') !== false) {
 			return true;
 		}
diff --git a/setup/backup.class.inc.php b/setup/backup.class.inc.php
index ac71952c0..1eeb0254b 100644
--- a/setup/backup.class.inc.php
+++ b/setup/backup.class.inc.php
@@ -16,7 +16,7 @@
 //   You should have received a copy of the GNU Affero General Public License
 //   along with iTop. If not, see <http://www.gnu.org/licenses/>
 
-require_once('tar.php');
+require_once(APPROOT.'core/tar-itop.class.inc.php');
 
 interface BackupArchive
 {
@@ -308,7 +308,7 @@ if (class_exists('ZipArchive')) // The setup must be able to start even if the "
 		{
 			$this->LogInfo("Creating backup: '$sTargetFile.tar.gz'");
 
-			$oArchive = new ArchiveTar($sTargetFile.'.tar.gz');
+			$oArchive = new ITopArchiveTar($sTargetFile.'.tar.gz');
 
 			$sTmpFolder = APPROOT.'data/tmp-backup-'.rand(10000, getrandmax());
 			$aFiles = $this->PrepareFilesToBackup($sSourceConfigFile, $sTmpFolder);
@@ -710,18 +710,14 @@ if (class_exists('ZipArchive')) // The setup must be able to start even if the "
 
 class TarGzArchive implements BackupArchive
 {
-	/*
-	 * @var ArchiveTar
-	 */
+	/** @var \ITopArchiveTar $oArchive */
 	protected $oArchive;
-	/*
-	 * string[]
-	 */
+	/** @var string[] $aFiles */
 	protected $aFiles = null;
 
 	public function __construct($sFile)
 	{
-		$this->oArchive = new ArchiveTar($sFile);
+		$this->oArchive = new ITopArchiveTar($sFile);
 	}
 
 	/**