If these apply to you:

• encountering problems creating a site backup from the Administration > Backup and Restore page
• automatic daily backups do not work anymore
• last working backup size without attachments is large (say over 500Mb)

You may want to consider an alternative backup strategy. As you may have already discovered, the built in backup functionality in Confluence requires a lot of memory to run. In some cases, increasing the total memory allocated your Confluence instance will still not help.

In these circumstances we recommend that you:

• Create a backup or dump of your database using tools provided by your database
• Create a backup of your Confluence home directory

We want to stress that creating these two backups is just as good as having a Confluence backup. You will be able to restore your whole site, including all data, attachments and configuration information intact with these two backups. We have written up a document on how to do this here.