3.16.4 release

Author: release-controller[bot]

docs/backup.config-example

@@ -21,6 +21,13 @@ GHE_NUM_SNAPSHOTS=10
 # Instead, ghe-prune-snapshots will need to be invoked separately via cron
 #GHE_PRUNING_SCHEDULED=yes
 
+# If --incremental is used to generate incremental MySQL backups with ghe-backup,
+# then you need to specify how many cycles of full and incremental backups will be 
+# performed before the next full backup is created.
+# For example, if `GHE_INCREMENTAL_BACKUP_MAX` is set to 14, backup-utils will 
+# run 1 full backup and then 13 incremental backups before performing another full backup on the next cycle.
+#GHE_INCREMENTAL_MAX_BACKUPS=14
+
 # If GHE_ROUTE_VERIFICATION is set to true then ghe-repository-backup and
 # ghe-storage-backup will issue a warning if the repositories and objects in
 # the backup do not match the pre-backup inventory of routes.

docs/getting-started.md

@@ -37,5 +37,5 @@
 
 [1]: https://github.com/github/backup-utils/releases
 [2]: https://github.com/github/backup-utils/releases/tag/v2.11.4
-[3]: https://github.com/github/backup-utils/blob/master/docs/backup.config-example
+[3]: https://github.com/github/enterprise-backup-site/blob/master/docs/backup.config-example
 [4]: https://docs.github.com/enterprise-server/admin/configuration/configuring-your-enterprise/accessing-the-administrative-shell-ssh

docs/incremental-mysql-backups-and-restores.md

@@ -0,0 +1,38 @@
+# Incremental MySQL Backups and Restores
+
+Customers who have large MySQL databases who wish to save storage space can use the `--incremental` flag with `ghe-backup` and `ghe-restore`.
+Using this flag performs backups for other parts of GHES as normal, but only performs a MySQL backup of the changes to the database from the previous snapshot.
+For larger databases this can conserve a lot of storage space for backups.
+
+## Configuring number of backups
+
+In your backup.config file you will need to set the variable `GHE_INCREMENTAL_MAX_BACKUPS`.
+This variable determines how many cycles of full and incremental backups will be performed before the next full backup is created.
+For example, if `GHE_INCREMENTAL_MAX_BACKUPS` is set to 14, backup-utils will run 1 full backup and then 13 incremental backups before performing another full backup on the next cycle.
+
+Incremental backups require the previous snapshot backups before them to work.
+This means they do not follow the pruning strategy based on `GHE_NUM_SNAPSHOTS`.
+
+## Performing incremental backups
+
+To perform incremental backups:
+
+`bin/ghe-backup --incremental`
+
+the program will detect whether it needs to performa full or incremental snapshot based on what is currently in `GHE_DATA_DIR`.
+
+To see what snapshots are part of your full and incremental backups, you can reference `GHE_DATA_DIR/inc_full_backup` and `GHE_DATA_DIR/inc_snapshot_data`, respectively.
+
+## Performing incremental restores
+
+To perform incremental restores:
+
+`bin/ghe-restore --incremental -s <snapshot-id>`
+
+The program will use the MySQL folders from each previous incremental backup and the full backup to restore the database.
+
+:warning: Incremental restores require the other snapshots in the cycle to complete a restore. Erasing snapshot directories that are part of a cycle corrupts the restore and makes it impossible to restore for the MySQL database.
+
+### Previous cycles
+
+To ensure there is a rolling window of mySQL backups, incremental MySQL backups from the cycle before the current one are kept.  Those snapshots are pre-pended with `inc_previous`. To perform a restore from there, just use the full directory name for the snapshot ID.

docs/usage.md

@@ -112,7 +112,8 @@ Please refer to [GHES Documentation](https://docs.github.com/en/enterprise-serve
 
 ## Incremental MySQL Backups and Restores
 
-Incremental MySQL backup has been deprecated since 3.17 due to data integrity concerns. Restoring backups created with incremental backups remains supported for compatibility reasons.
+If you are interested in performing incremental backups of the MySQL data in your GitHub Enterprise Server instance, see [Incremental MySQL Backups and Restores](incremental-mysql-backups-and-restores.md) for details.
+
 ## Rsync compression
 
 From backup-utils v3.11.0 onwards, we have disabled rsync compression by default to improve transfer speed and reduce CPU usage during the transfer process.