diff --git a/code/controllers/CMSMain.php b/code/controllers/CMSMain.php
index d65db28a..114ea3ab 100644
--- a/code/controllers/CMSMain.php
+++ b/code/controllers/CMSMain.php
@@ -53,7 +53,6 @@ class CMSMain extends LeftAndMain implements CurrentPageIdentifier, PermissionPr
 
 	private static $allowed_actions = array(
 		'archive',
-		'buildbrokenlinks',
 		'deleteitems',
 		'DeleteItemsForm',
 		'dialog',
@@ -1269,42 +1268,6 @@ class CMSMain extends LeftAndMain implements CurrentPageIdentifier, PermissionPr
 		return $this->batchactions()->batchActionList();
 	}
 
-	public function buildbrokenlinks($request) {
-		// Protect against CSRF on destructive action
-		if(!SecurityToken::inst()->checkRequest($request)) return $this->httpError(400);
-
-		increase_time_limit_to();
-		increase_memory_limit_to();
-
-		if($this->urlParams['ID']) {
-			$newPageSet[] = DataObject::get_by_id("Page", $this->urlParams['ID']);
-		} else {
-			$pages = DataObject::get("Page");
-			foreach($pages as $page) $newPageSet[] = $page;
-			$pages = null;
-		}
-
-		$content = new HTMLEditorField('Content');
-		$download = new HTMLEditorField('Download');
-
-		foreach($newPageSet as $i => $page) {
-			$page->HasBrokenLink = 0;
-			$page->HasBrokenFile = 0;
-
-			$content->setValue($page->Content);
-			$content->saveInto($page);
-
-			$download->setValue($page->Download);
-			$download->saveInto($page);
-
-			echo "<li>$page->Title (link:$page->HasBrokenLink, file:$page->HasBrokenFile)";
-
-			$page->writeWithoutVersion();
-			$page->destroy();
-			$newPageSet[$i] = null;
-		}
-	}
-
 	public function publishall($request) {
 		if(!Permission::check('ADMIN')) return Security::permissionFailure($this);
 
diff --git a/code/forms/FolderUnusedAssetsField.php b/code/forms/FolderUnusedAssetsField.php
deleted file mode 100644
index c4af4c3a..00000000
--- a/code/forms/FolderUnusedAssetsField.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-/**
- * @package cms
- * @subpackage filesystem
- */
-class Folder_UnusedAssetsField extends CompositeField {
-
-	/**
-	 * @var Folder
-	 */
-	protected $folder;
-
-	public function __construct($folder) {
-		$this->folder = $folder;
-		parent::__construct(new FieldList());
-	}
-
-	public function getChildren() {
-		if($this->children->Count() == 0) {
-			$inlineFormAction = new InlineFormAction("delete_unused_thumbnails", _t('Folder.DELETEUNUSEDTHUMBNAILS', 'Delete unused thumbnails'));
-			$inlineFormAction->includeDefaultJS(false) ;
-
-			$this->children = new FieldList(
-				new LiteralField( "UnusedAssets", "<h2>"._t('Folder.UNUSEDFILESTITLE', 'Unused files')."</h2>" ),
-				$this->getAssetList(),
-				new FieldGroup(
-					new LiteralField( "UnusedThumbnails", "<h2>"._t('Folder.UNUSEDTHUMBNAILSTITLE', 'Unused thumbnails')."</h2>"),
-					$inlineFormAction
-				)
-			);
-			$this->children->setForm($this->form);
-		}
-		return $this->children;
-	}
-
-	public function FieldHolder($properties = array()) {
-		$output = "";
-		foreach($this->getChildren() as $child) {
-			$output .= $child->FieldHolder();
-		}
-		return $output;
-	}
-
-
-	/**
-	 * Creates table for displaying unused files.
-	 *
-	 * @return GridField
-	 */
-	protected function getAssetList() {
-		$where = $this->folder->getUnusedFilesListFilter();
-		$files = File::get()->where($where);
-		$field = new GridField('AssetList', false, $files);
-		return $field;
-	}
-}
diff --git a/code/model/SiteTree.php b/code/model/SiteTree.php
index 2f8e4426..d5308ba8 100755
--- a/code/model/SiteTree.php
+++ b/code/model/SiteTree.php
@@ -1464,17 +1464,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 				DB::alteration_message('Contact Us page created', 'created');
 			}
 		}
-
-		// schema migration
-		// @todo Move to migration task once infrastructure is implemented
-		if($this->class == 'SiteTree') {
-			$conn = DB::get_schema();
-			// only execute command if fields haven't been renamed to _obsolete_<fieldname> already by the task
-			if($conn->hasField('SiteTree' ,'Viewers')) {
-				$task = new UpgradeSiteTreePermissionSchemaTask();
-				$task->run(new SS_HTTPRequest('GET','/'));
-			}
-		}
 	}
 
 	protected function onBeforeWrite() {
diff --git a/tasks/UpgradeSiteTreePermissionSchemaTask.php b/tasks/UpgradeSiteTreePermissionSchemaTask.php
deleted file mode 100644
index 8813a807..00000000
--- a/tasks/UpgradeSiteTreePermissionSchemaTask.php
+++ /dev/null
@@ -1,55 +0,0 @@
-<?php
-
-use SilverStripe\ORM\DB;
-use SilverStripe\ORM\DataObject;
-
-/**
- * @package cms
- * @subpackage tasks
- */
-class UpgradeSiteTreePermissionSchemaTask extends BuildTask {
-
-	private static $allowed_actions = array(
-		'*' => 'ADMIN'
-	);
-
-	protected $title = 'Upgrade SiteTree Permissions Schema';
-
-	protected $description = "Move data from legacy columns to new schema introduced in SilverStripe 2.1.<br />
-		SiteTree->Viewers to SiteTree->CanViewType<br />
-		SiteTree->Editors to SiteTree->CanEditType<br />
-		SiteTree->ViewersGroup to SiteTree->ViewerGroups (has_one to many_many)<br />
-		SiteTree->Editorsroup to SiteTree->EditorGroups (has_one to many_many)<br />
-		See http://open.silverstripe.com/ticket/2847
-	";
-
-	public function run($request) {
-		// transfer values for changed column name
-		foreach(array('SiteTree','SiteTree_Live','SiteTree_versions') as $table) {
-			DB::prepared_query("UPDATE \"{$table}\" SET \"CanViewType\" = ?", array('Viewers'));
-			DB::prepared_query("UPDATE \"{$table}\" SET \"CanEditType\" = ?", array('Editors'));
-		}
-		//Debug::message('Moved SiteTree->Viewers to SiteTree->CanViewType');
-		//Debug::message('Moved SiteTree->Editors to SiteTree->CanEditType');
-
-		// convert has_many to many_many
-		$pageIDs = DB::query("SELECT ID FROM SiteTree")->column('ID');
-		foreach($pageIDs as $pageID) {
-			$page = DataObject::get_by_id('SiteTree', $pageID);
-			if($page->ViewersGroup && DataObject::get_by_id("SilverStripe\\Security\\Group", $page->ViewersGroup)) $page->ViewerGroups()->add($page->ViewersGroup);
-			if($page->EditorsGroup && DataObject::get_by_id("SilverStripe\\Security\\Group", $page->EditorsGroup)) $page->EditorGroups()->add($page->EditorsGroup);
-
-			$page->destroy();
-			unset($page);
-		}
-		//Debug::message('SiteTree->ViewersGroup to SiteTree->ViewerGroups (has_one to many_many)');
-		//Debug::message('SiteTree->EditorsGroup to SiteTree->EditorGroups (has_one to many_many)');
-
-		// rename legacy columns
-		foreach(array('SiteTree','SiteTree_Live','SiteTree_versions') as $table) {
-			foreach(array('Viewers','Editors','ViewersGroup','EditorsGroup') as $field) {
-				 DB::get_conn()->dontRequireField($table, $field);
-			}
-		}
-	}
-}