diff --git a/bundles/nextcloud/README.md b/bundles/nextcloud/README.md
new file mode 100644
index 0000000..bdd25d2
--- /dev/null
+++ b/bundles/nextcloud/README.md
@@ -0,0 +1,71 @@
+Nextcloud
+=========
+
+import iphone pictures
+----------------------
+
+Use Photos app on macOS
+- select library in the left sidebar
+- select the pictures
+- in menu bar open File > Export Unmodified Original for X Photos
+
+The only reliable way to get some files creation time is being lost with rsync, so
+we need to embed those timestamps on macos first:
+
+```sh
+PHOTOS_PATH="/Users/mwiegand/Desktop/photos"
+bin/timestamp_icloud_photos_for_nextcloud -d "$PHOTOS_PATH"
+rsync -avh --progress --rsync-path="sudo rsync" "$PHOTOS_PATH/" ckn@10.0.0.2:/var/lib/nextcloud/ckn/files/SofortUpload/AutoSort/
+```
+
+preview generator
+-----------------
+
+```
+sudo -u www-data php /opt/nextcloud/occ preview:generate-all -w "$(nproc)" -n -vvv
+```
+
+This index speeds up preview generator dramatically:
+```sh
+CREATE INDEX CONCURRENTLY oc_filecache_path_hash_idx
+ON oc_filecache (path_hash);
+```
+
+delete previews:
+```sh
+psql nextcloud -x -c "DELETE FROM oc_previews;"
+rm -rf /var/lib/nextcloud/appdata_oci6dw1woodz/preview/*
+```
+
+https://docs.nextcloud.com/server/stable/admin_manual/configuration_files/previews_configuration.html#maximum-preview-size
+```php
+    'preview_max_x' => 1920,
+    'preview_max_y' => 1920,
+    'preview_max_scale_factor' => 4,
+```
+
+https://github.com/nextcloud/previewgenerator?tab=readme-ov-file#i-dont-want-to-generate-all-the-preview-sizes
+```sh
+sudo -u www-data php /opt/nextcloud/occ config:app:set --value="64 256" previewgenerator squareSizes
+sudo -u www-data php /opt/nextcloud/occ config:app:set --value="" previewgenerator fillWidthHeightSizes # changed
+sudo -u www-data php /opt/nextcloud/occ config:app:set --value="" previewgenerator widthSizes
+sudo -u www-data php /opt/nextcloud/occ config:app:set --value="" previewgenerator heightSizes
+sudo -u www-data php /opt/nextcloud/occ config:app:set preview jpeg_quality --value="75"
+sudo -u www-data php /opt/nextcloud/occ config:app:set --value=0 --type=integer previewgenerator job_max_previews # in favour of systemd timer
+```
+
+gen previews
+```sh
+php /opt/nextcloud/occ preview:generate-all --workers="$(nproc)" --no-interaction -vvv
+```
+
+check preview geenration
+```sh
+find /var/lib/nextcloud/appdata_oci6dw1woodz/preview
+# /var/lib/nextcloud/appdata_oci6dw1woodz/preview/6/9/1/f/7/b/4/2822419/64-64-crop.jpg
+# /var/lib/nextcloud/appdata_oci6dw1woodz/preview/6/9/1/f/7/b/4/2822419/256-256-crop.jpg
+# /var/lib/nextcloud/appdata_oci6dw1woodz/preview/6/9/1/f/7/b/4/2822419/1280-1920-max.jpg
+
+du -sh /var/lib/nextcloud/appdata_oci6dw1woodz/preview
+# 28G	/var/lib/nextcloud/appdata_oci6dw1woodz/preview
+```
\ No newline at end of file
diff --git a/bundles/nextcloud/files/rescan b/bundles/nextcloud/files/rescan
deleted file mode 100644
index 9fb8234..0000000
--- a/bundles/nextcloud/files/rescan
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/bin/bash
-
-php /opt/nextcloud/occ files:scan --all
-php /opt/nextcloud/occ files:scan-app-data
-#php /opt/nextcloud/occ preview:generate-all
diff --git a/bundles/nextcloud/items.py b/bundles/nextcloud/items.py
index 700bc77..f4aa122 100644
--- a/bundles/nextcloud/items.py
+++ b/bundles/nextcloud/items.py
@@ -146,15 +146,3 @@ actions['nextcloud_add_missing_inidces'] = {
         f'action:extract_nextcloud',
     ],
 }
-
-# RESCAN
-
-files['/opt/nextcloud_rescan'] = {
-    'source': 'rescan',
-    'owner': 'www-data',
-    'group': 'www-data',
-    'mode': '550',
-    'needs': [
-        'action:extract_nextcloud',
-    ],
-}
diff --git a/bundles/nextcloud/metadata.py b/bundles/nextcloud/metadata.py
index b3ea402..ad7c652 100644
--- a/bundles/nextcloud/metadata.py
+++ b/bundles/nextcloud/metadata.py
@@ -1,5 +1,5 @@
-import string
-from uuid import UUID
+from shlex import quote
+
 
 defaults = {
     'apt': {
@@ -85,11 +85,35 @@ defaults = {
             'user': 'www-data',
             'kill_mode': 'process',
         },
-        'nextcloud-rescan': {
-            'command': '/opt/nextcloud_rescan',
-            'when': 'Sun 00:00:00',
+        'nextcloud-scan-app-data': {
+            'command': '/usr/bin/php /opt/nextcloud/occ files:scan-app-data',
+            'when': 'yearly',
             'user': 'www-data',
         },
+        'nextcloud-scan-files': {
+            'command': '/usr/bin/php /opt/nextcloud/occ files:scan --all',
+            'when': 'weekly',
+            'user': 'www-data',
+            'after': {
+                'nextcloud-scan-app-data.service',
+            },
+        },
+        'nextcloud-generate-all-previews': {
+            'command': '/bin/bash -c ' + quote('php /opt/nextcloud/occ preview:generate-all --workers="$(nproc)" --no-interaction -vvv'),
+            'when': 'monthly',
+            'user': 'www-data',
+            'after': {
+                'nextcloud-scan-files.service',
+            },
+        },
+        'nextcloud-generate-new-previews': {
+            'command': '/usr/bin/php /opt/nextcloud/occ preview:pre-generate',
+            'when': '*:0/5', # every 5 minutes
+            'user': 'www-data',
+            'after': {
+                'nextcloud-generate-all-previews.service',
+            },
+        },
     },
 }
 
@@ -134,10 +158,18 @@ def config(metadata):
                     '127.0.0.1',
                     metadata.get('nextcloud/hostname'),
                 ],
+                'enabledPreviewProviders': [
+                    'OC\\Preview\\Image',
+                    'OC\\Preview\\Movie',
+                    'OC\\Preview\\HEIC',
+                ],
+                'preview_max_x': 1920,
+                'preview_max_y': 1920,
+                'preview_max_scale_factor': 4,
                 'log_type': 'syslog',
                 'syslog_tag': 'nextcloud',
                 'logfile': '',
-                'loglevel': 3,
+                'loglevel': 2,
                 'default_phone_region': 'DE',
                 'versions_retention_obligation': 'auto, 90',
                 'simpleSignUpLink.shown': False,