diff --git a/roles/openvpn/defaults/main.yml b/roles/openvpn/defaults/main.yml
index fbf8278..a63b300 100644
--- a/roles/openvpn/defaults/main.yml
+++ b/roles/openvpn/defaults/main.yml
@@ -41,3 +41,5 @@ ovpn_daemon_defaults:
   push_routes: []
   client_to_client: False
   duplicate_dn: False
+  # rcvbuf: 524288
+  # sndbuf: 524288
diff --git a/roles/openvpn/templates/openvpn.conf.j2 b/roles/openvpn/templates/openvpn.conf.j2
index b718d49..6cacd4d 100644
--- a/roles/openvpn/templates/openvpn.conf.j2
+++ b/roles/openvpn/templates/openvpn.conf.j2
@@ -98,3 +98,14 @@ keepalive 10 60
 {% if item.proto == 'udp' %}
 mtu-test
 {% endif %}
+
+{% if item.rcvbuf is defined %}
+rcvbuf {{ item.rcvbuf }}
+{% endif %}
+{% if item.sndbuf is defined %}
+sndbuf {{ item.sndbuf }}
+{% endif %}
+
+{% if item.proto == 'udp' %}
+fast-io
+{% endif %}
diff --git a/roles/zabbix_agent/vars/Debian-10.yml b/roles/zabbix_agent/vars/Debian-10.yml
index 7bf41c0..b09c3a4 100644
--- a/roles/zabbix_agent/vars/Debian-10.yml
+++ b/roles/zabbix_agent/vars/Debian-10.yml
@@ -11,3 +11,4 @@ zabbix_agent_packages:
   - lm-sensors
   - patch
   - fping
+  - libstatistics-descriptive-perl
diff --git a/roles/zabbix_agent/vars/Debian-9.yml b/roles/zabbix_agent/vars/Debian-9.yml
index 7bf41c0..b09c3a4 100644
--- a/roles/zabbix_agent/vars/Debian-9.yml
+++ b/roles/zabbix_agent/vars/Debian-9.yml
@@ -11,3 +11,4 @@ zabbix_agent_packages:
   - lm-sensors
   - patch
   - fping
+  - libstatistics-descriptive-perl