# Maintenance¶

There are various maintenance tasks which can be performed to maintain a healthy TYPO3 CMS installation with the file abstraction layer.

Two base tasks provided by the Scheduler are related to the file abstraction layer.

File abstraction layer: Update storage index

This task goes through a storage and makes sures that every file is properly indexed. When files are manipulated only via the TYPO3 CMS backend, they are always indexed. However if files get added via other means (e.g. FTP) or if some storages are based on drivers accessing remote systems, it is crucial to run this task regularly so that the TYPO3 CMS installation knows about all existing files in order to make them available to users.

This task is defined per storage.

File abstraction layer: Extract metadata in storage

This task goes through all files in a storage and updates their metadata. Again this is especially important when files can be manipulated by other means or actually reside on external systems.

This task is defined per storage.

## Processed files¶

If you change some graphics-related settings, it may be necessary to force a regeneration of all processed files. This can be achieved by deleting all existing processed files in Admin Tools > Maintenance > Remove Temporary Assets.

Here you can choose to delete all files in fileadmin/_processed_/

This cleanup is also good if processed files have accumulated for a long time. Many of them may then be obsolete.