diff --git a/README.md b/README.md
index 4d5e3bb..a666a88 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,7 @@ Using [NextCloud](https://nextcloud.com/)
 - [command](#command)
 - [maintenance mode](#maintenance-mode)
   - [scan files](#scan-files)
+  - [preview generator](#preview-generator)
   - [repair tree](#repair-tree)
   - [delete file locks](#delete-file-locks)
 - [Setup](#setup)
@@ -14,7 +15,6 @@ Using [NextCloud](https://nextcloud.com/)
   - [Add helm chart](#add-helm-chart)
   - [Update Helm chart](#update-helm-chart)
   - [Install / Update](#install--update)
-- [backups](#backups)
 
 ## command
 
@@ -29,6 +29,21 @@ su -s /bin/bash www-data -c "php -d memory_limit=-1 /var/www/html/occ maintenanc
 
 ``` bash
 su -s /bin/bash www-data -c "php -d memory_limit=-1 /var/www/html/occ files:scan --all"
+
+```
+
+### preview generator
+
+<https://apps.nextcloud.com/apps/previewgenerator>
+
+``` bash
+su -s /bin/bash www-data -c "./occ preview:generate-all -vvv"
+su -s /bin/bash www-data -c "./occ preview:generate-all --path=marcio.fernandes/files/Photos -vvv"
+```
+
+``` bash
+# cron job
+ php /var/www/nextcloud/occ preview:pre-generate 
 ```
 
 ### repair tree
diff --git a/nextcloud/values.yaml b/nextcloud/values.yaml
index e5c4c68..0ecf033 100644
--- a/nextcloud/values.yaml
+++ b/nextcloud/values.yaml
@@ -53,6 +53,34 @@ resources:
     cpu: "0.5"
     memory: 512Mi
 
+
+## Cronjob to execute Nextcloud background tasks
+## ref: https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/background_jobs_configuration.html#cron
+##
+cronjob:
+  enabled: true
+
+  ## Cronjob sidecar resource requests and limits
+  ## ref: http://kubernetes.io/docs/user-guide/compute-resources/
+  ##
+  resources: {}
+
+  # Allow configuration of lifecycle hooks
+  # ref: https://kubernetes.io/docs/tasks/configure-pod-container/attach-handler-lifecycle-event/
+  lifecycle: {}
+    # postStartCommand: []
+    # preStopCommand: []
+  # Set securityContext parameters. For example, you may need to define runAsNonRoot directive
+  securityContext: {}
+  #   runAsUser: 33
+  #   runAsGroup: 33
+  #   runAsNonRoot: true
+  #   readOnlyRootFilesystem: true
+
+  # The command the cronjob container executes.
+  command:
+  - /cron.sh
+
 nextcloud:
   extraVolumes:
     - name: mf-documents
diff --git a/persistance-volumes-claims.yaml b/persistance-volumes-claims.yaml
index 58e774b..dd6dafb 100644
--- a/persistance-volumes-claims.yaml
+++ b/persistance-volumes-claims.yaml
@@ -7,7 +7,7 @@ metadata:
   namespace: cloud-limbosolutions-com
 spec:
   storageClassName: "" # isto tem mesmo de ficar senão não funciona não sei pq.. tem de ficar ""
-  volumeName: mf-documents-storage-limbosolutions-co
+  volumeName: mf-documents-storage-limbosolutions-com
   accessModes:
   - ReadWriteMany
   resources: