backup.sh: Only purge when doing full backups

Signed-off-by: Florian Pritz <bluewind@xinu.at>

1 files changed, 7 insertions, 2 deletions

diff --git a/backup.sh b/backup.sh
index a674819..38e2a89 100755
--- a/backup.sh
+++ b/backup.sh
@@ -137,8 +137,13 @@ backup_borg() {
 	fi
 
 	borg create "${options[@]}" "$dst::$backup_prefix-$(date "+%Y%m%d-%H%M%S")" "${src[@]}"
-	borg prune --prefix "backup-" --keep-within 7d --keep-daily 7 --keep-weekly 12 --keep-monthly 6 --keep-yearly 0 -v "$dst"
-	borg prune --prefix "partial-" --keep-within 7d --keep-daily 7 --keep-weekly 12 --keep-monthly 6 --keep-yearly 0 -v "$dst"
+
+	# Only purge when doing full backups. Increases partial backup speed and
+	# ensure that we have at least one recent full backup when we purge.
+	if [[ $backup_prefix == 'backup-' ]]; then
+		borg prune --prefix "backup-" --keep-within 7d --keep-daily 7 --keep-weekly 12 --keep-monthly 6 --keep-yearly 0 -v "$dst"
+		borg prune --prefix "partial-" --keep-within 7d --keep-daily 7 --keep-weekly 12 --keep-monthly 6 --keep-yearly 0 -v "$dst"
+	fi
 }
 
 ### support functions below ###