Merge pull request #462 from github/djj/update-docs-for-pruning

Add details about snapshot pruning

Author: davidjarzebowski

docs/scheduling-backups.md

@@ -4,7 +4,6 @@ Regular backups should be scheduled using `cron(8)` or similar command
 scheduling service on the backup host. The backup frequency will dictate the
 worst case [recovery point objective (RPO)][1] in your backup plan. We recommend
 hourly backups at the least.
-
 ## Example scheduling usage
 
 The following examples assume the Backup Utilities are installed under
@@ -17,30 +16,36 @@ based on the frequency of backups. The ten most recent snapshots are retained by
 default. The number should be adjusted based on backup frequency and available
 storage.
 
-By default all expired and incomplete snapshots are deleted at the end of the main
-backup process `ghe-backup`. If pruning these snapshots takes a long time you can
-choose to disable the pruning process from the backup run and schedule it separately.
-This can be achieved by enabling the `GHE_PRUNING_SCHEDULED` option in `backup.config`.
-Please note if this option is enabled, you will need to schedule the pruning script `ghe-prune-snapshots`
-using `cron` or similar command scheduling service on the backup host.
-
 To schedule hourly backup snapshots with verbose informational output written to
 a log file and errors generating an email:
+```
+[email protected]
 
-    [email protected]
-
-    0 * * * * /opt/backup-utils/bin/ghe-backup -v 1>>/opt/backup-utils/backup.log 2>&1
+0 * * * * /opt/backup-utils/bin/ghe-backup -v 1>>/opt/backup-utils/backup.log 2>&1
+```
 
 To schedule nightly backup snapshots instead, use:
 
-    [email protected]
+```
+[email protected]
 
-    0 0 * * * /opt/backup-utils/bin/ghe-backup -v 1>>/opt/backup-utils/backup.log 2>&1
+0 0 * * * /opt/backup-utils/bin/ghe-backup -v 1>>/opt/backup-utils/backup.log 2>&1
+```
+
+### Example snapshot pruning 
+
+By default all expired and incomplete snapshots are deleted at the end of the main
+backup process `ghe-backup`. If pruning these snapshots takes a long time you can
+choose to disable the pruning process from the backup run and schedule it separately.
+This can be achieved by enabling the `GHE_PRUNING_SCHEDULED` option in `backup.config`.
+Please note that this option is only avilable for `backup-utils` >= v3.10.0, if this option is enabled you will need to schedule the pruning script `ghe-prune-snapshots` using `cron` or a similar command scheduling service on the backup host.
 
 To schedule daily snapshot pruning, use:
 
-    [email protected]
+```
+[email protected]
 
-    0 3 * * * /opt/backup-utils/share/github-backup-utils/ghe-prune-snapshots 1>>/opt/backup-utils/prune-snapshots.log 2>&1
+0 3 * * * /opt/backup-utils/share/github-backup-utils/ghe-prune-snapshots 1>>/opt/backup-utils/prune-snapshots.log 2>&1
+```
 
 [1]: https://en.wikipedia.org/wiki/Recovery_point_objective