> For the complete documentation index, see [llms.txt](https://rc.sunbird.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://rc.sunbird.org/v1.0.0/use/developers-guide/backup-and-restore/cassandra/incremental-backup-method.md). # Incremental backup method Enabling incremental backup in Cassandra involves modifying the `incremental_backups`value to `true` in the `cassandra.yaml` file. Once enabled, Cassandra establishes hard links to flushed memtables in SSTables within a backup directory located in the keyspace data directory. Incremental backups in Cassandra exclusively consist of new SSTable files, dependent on the last created snapshot. This approach minimizes disk space usage as it solely includes links to recently generated SSTable files from the previous full snapshot. ## Advantages * Decreases disk space requirements * Reduces transfer costs ## Disadvantages * Cassandra does not automatically clear incremental backup files, necessitating the creation of a custom script for their removal * Generates numerous small-sized files during backup, complicating file management and recovery procedures * It is not possible to selectively choose specific column families for incremental backup. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://rc.sunbird.org/v1.0.0/use/developers-guide/backup-and-restore/cassandra/incremental-backup-method.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.