# How to clean up nextcloud-data/appdata\_\* and /updater-\*

**URL:** <https://help.nextcloud.com/t/how-to-clean-up-nextcloud-data-appdata-and-updater/123746>\
**Category:** ℹ️ Support\
**Created:** [September 15, 2021, 8:26pm UTC](https://help.nextcloud.com/t/how-to-clean-up-nextcloud-data-appdata-and-updater/123746 "2021-09-15T20:26:28Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![gas85](https://help.nextcloud.com/user_avatar/help.nextcloud.com/gas85/32/7772_2.png) [@gas85](https://help.nextcloud.com/u/gas85)\
**Post date:** [September 21, 2021, 9:45am UTC](https://help.nextcloud.com/t/how-to-clean-up-nextcloud-data-appdata-and-updater/123746/7 "2021-09-21T09:45:48Z")

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As I linked above you can adjust config, my current config is:

> [@Previews / data size](https://help.nextcloud.com/t/previews-data-size/46990/2):
>
> ```auto
> 'enable_previews' => true,
> 'enabledPreviewProviders' => 
> array (
> 0 => 'OC\\Preview\\PNG',
> 1 => 'OC\\Preview\\JPEG',
> 2 => 'OC\\Preview\\GIF',
> 3 => 'OC\\Preview\\BMP',
> 4 => 'OC\\Preview\\XBitmap',
> 5 => 'OC\\Preview\\Movie',
> 6 => 'OC\\Preview\\PDF',
> 7 => 'OC\\Preview\\MP3',
> 8 => 'OC\\Preview\\TXT',
> 9 => 'OC\\Preview\\MarkDown',
> ),
> 'preview_max_x' => 1080,
> 'preview_max_y' => 1920,
> 'jpeg_quality' => 90,
> 
> ```

Read more about:  
[https://ownyourbits.com/2019/06/29/understanding-and-improving-nextcloud-previews/](https://ownyourbits.com/2019/06/29/understanding-and-improving-nextcloud-previews/)

And than you need to regenerate previews again:

> [@Gallery app not using previews generated by Preview Generator](https://help.nextcloud.com/t/gallery-app-not-using-previews-generated-by-preview-generator/21137/9):
>
> P.S. It turns that changing of config.php will _not_ automatically recreate smaller/bigger previews. This is how to do it [https://github.com/rullzer/previewgenerator/issues/94#issuecomment-355745556](https://github.com/rullzer/previewgenerator/issues/94#issuecomment-355745556) run pregenerate command afterwards.

Short summery from the Github:

#### To “reset” the preview cache

1. Stop Webserver (apache / nginx)
2. Moved the appdata\_instaceName/preview folder outside the appdata folder. You can just remove it if you are confident.
3. Run `sudo -u www-data /usr/bin/php /var/www/nextcloud/occ files:scan-app-data` to fix database
4. Start Webserver and Test everything works
5. Finish up (delete moved folder, etc).
6. Run pregenerate command afterwards.

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_[View the full topic](https://help.nextcloud.com/t/how-to-clean-up-nextcloud-data-appdata-and-updater/123746)._