Code optimizations to reduce disk writes on SONiC switches

dockers/docker-orchagent/docker-init.j2

@@ -3,7 +3,7 @@
 mkdir -p /etc/swss/config.d/
 mkdir -p /etc/supervisor/
 mkdir -p /etc/supervisor/conf.d/
-
+mkdir -p /dev/shm/supervisor/
 
 CFGGEN_PARAMS=" \
     -d \

files/build_templates/docker_image_ctl.j2

@@ -631,6 +631,7 @@ start() {
 {%- endif %}
         -e RUNTIME_OWNER=local \
         --uts=host \{# W/A: this should be set per-docker, for those dockers which really need host's UTS namespace #}
+	--tmpfs /var/log/supervisor:rw \
 {%- if install_debug_image == "y" %}
         -v /src:/src:ro -v /debug:/debug:rw \
 {%- endif %}

files/build_templates/sonic_debian_extension.j2

@@ -104,6 +104,11 @@ sudo dpkg --root=$FILESYSTEM_ROOT -i $debs_path/sonic-nettools_*.deb || \
     sudo LANG=C DEBIAN_FRONTEND=noninteractive chroot $FILESYSTEM_ROOT apt-get -y install -f
 sudo setcap 'cap_net_raw=+ep' $FILESYSTEM_ROOT/usr/bin/wol
 
+# This is needed for moving monit logs, state and logrotate status to tmpfs
+sudo bash -c "echo \"d	/dev/shm/monit/ 0755 root root\" > $FILESYSTEM_ROOT/etc/tmpfiles.d/tmpfs-monit.conf"
+sudo bash -c "echo \"d	/dev/shm/logrotate/ 0755 root root\" > $FILESYSTEM_ROOT/etc/tmpfiles.d/tmpfs-logrotate.conf"
+
+
 # Install a patched version of ifupdown2  (and its dependencies via 'apt-get -y install -f')
 sudo dpkg --root=$FILESYSTEM_ROOT -i $debs_path/ifupdown2_*.deb || \
     sudo LANG=C DEBIAN_FRONTEND=noninteractive chroot $FILESYSTEM_ROOT apt-get -y install -f

files/image_config/logrotate/logrotateOverride.conf

@@ -1,2 +1,6 @@
 [Unit]
-Requires=logrotate-config.service
+Requires=logrotate-config.service
+
+[Service]
+ExecStart=
+ExecStart=/usr/sbin/logrotate --state /dev/shm/logrotate/status /etc/logrotate.conf

files/image_config/monit/monitrc

@@ -38,15 +38,15 @@
 ## default the file is placed in $HOME/.monit.id.
 #
 # set idfile /var/.monit.id
-  set idfile /var/lib/monit/id
+  set idfile /dev/shm/monit/id
 #
 ## Set the location of the Monit state file which saves monitoring states
 ## on each cycle. By default the file is placed in $HOME/.monit.state. If
 ## the state file is stored on a persistent filesystem, Monit will recover
 ## the monitoring state across reboots. If it is on temporary filesystem, the
 ## state will be lost on reboot which may be convenient in some situations.
 #
-  set statefile /var/lib/monit/state
+  set statefile /dev/shm/monit/state
 #
 #
 
@@ -91,7 +91,7 @@
 ## available in the back end filesystem).
 #
   set eventqueue
-      basedir /var/lib/monit/events # set the base directory where events will be stored
+      basedir /dev/shm/monit/events # set the base directory where events will be stored
       slots 100                     # optionally limit the queue size
 #
 #

files/initramfs-tools/union-mount.j2

@@ -212,6 +212,9 @@ mkdir -p ${rootmnt}/boot
 mkdir -p ${rootmnt}/host/$image_dir/boot
 mount --bind ${rootmnt}/host/$image_dir/boot ${rootmnt}/boot
 
+## Mount the /tmp directory as tmpfs
+mount -t tmpfs -o rw,nosuid,nodev,size=25% tmpfs ${rootmnt}/tmp
+
 ## Mount loop device or tmpfs for /var/log
 if $logs_inram; then
     # NOTE: some platforms, when reaching initramfs stage, have a small

src/sonic-bgpcfgd/bgpcfgd/managers_bgp.py

@@ -387,7 +387,7 @@ def load_peers():
         Load peers from FRR.
         :return: set of peers, which are already installed in FRR
         """
-        command = ["vtysh", "-c", "show bgp vrfs json"]
+        command = ["vtysh", "-H", "/dev/null", "-c", "show bgp vrfs json"]
         ret_code, out, err = run_command(command)
         if ret_code == 0:
             js_vrf = json.loads(out)

src/sonic-bgpcfgd/bgpmon/bgpmon.py

@@ -77,7 +77,7 @@ def update_new_peer_states(self, peer_dict):
 
     # Get a new snapshot of BGP neighbors and store them in the "new" location
     def get_all_neigh_states(self):
-        cmd = ["vtysh", "-c", 'show bgp summary json']
+        cmd = ["vtysh", "-H", "/dev/null",  "-c", 'show bgp summary json']
         retry_attempt = 0
 
         while retry_attempt < self.MAX_RETRY_ATTEMPTS:

src/sonic-bgpcfgd/tests/test_bgp.py

@@ -32,7 +32,7 @@ def constructor(constants_path, bgp_router_id="", peer_type="general", with_lo0_
     }
 
     return_value_map = {
-        "['vtysh', '-c', 'show bgp vrfs json']": (0, "{\"vrfs\": {\"default\": {}}}", ""),
+        "['vtysh', '-H', '/dev/null', '-c', 'show bgp vrfs json']": (0, "{\"vrfs\": {\"default\": {}}}", ""),
         "['vtysh', '-c', 'show bgp vrf default neighbors json']": (0, "{\"10.10.10.1\": {}, \"20.20.20.1\": {}, \"fc00:10::1\": {}}", "")
     }