diff --git a/advanced/Scripts/webpage.sh b/advanced/Scripts/webpage.sh
index 8ef4d940..ec5f8e49 100755
--- a/advanced/Scripts/webpage.sh
+++ b/advanced/Scripts/webpage.sh
@@ -426,7 +426,7 @@ dhcp-leasefile=/etc/pihole/dhcp.leases
         echo "#quiet-dhcp6
 #enable-ra
 dhcp-option=option6:dns-server,[::]
-dhcp-range=::100,::1ff,constructor:${interface},ra-names,slaac,${leasetime}
+dhcp-range=::100,::1ff,constructor:${interface},ra-names,slaac,64,3600
 ra-param=*,0,0
 " >> "${dhcpconfig}"
     fi
@@ -716,7 +716,7 @@ RemoveCustomDNSAddress() {
     host="${args[3]}"
 
     if valid_ip "${ip}" || valid_ip6 "${ip}" ; then
-        sed -i "/${ip} ${host}/d" "${dnscustomfile}"
+        sed -i "/^${ip} ${host}$/d" "${dnscustomfile}"
     else
         echo -e "  ${CROSS} Invalid IP has been passed"
         exit 1
@@ -748,7 +748,7 @@ RemoveCustomCNAMERecord() {
     if [[ -n "${validDomain}" ]]; then
         validTarget="$(checkDomain "${target}")"
         if [[ -n "${validDomain}" ]]; then
-            sed -i "/cname=${validDomain},${validTarget}/d" "${dnscustomcnamefile}"
+            sed -i "/cname=${validDomain},${validTarget}$/d" "${dnscustomcnamefile}"
         else
             echo "  ${CROSS} Invalid Target Passed!"
             exit 1
diff --git a/automated install/basic-install.sh b/automated install/basic-install.sh
index 454daee4..96ca8c92 100755
--- a/automated install/basic-install.sh	
+++ b/automated install/basic-install.sh	
@@ -1944,9 +1944,17 @@ finalExports() {
 # Install the logrotate script
 installLogrotate() {
     local str="Installing latest logrotate script"
+    local target=/etc/pihole/logrotate
+
     printf "\\n  %b %s..." "${INFO}" "${str}"
+    if [[ -f ${target} ]]; then
+        printf "\\n\\t%b Existing logrotate file found. No changes made.\\n" "${INFO}"
+        # Return value isn't that important, using 2 to indicate that it's not a fatal error but
+        # the function did not complete. 
+        return 2
+    fi
     # Copy the file over from the local repo
-    install -D -m 644 -T ${PI_HOLE_LOCAL_REPO}/advanced/Templates/logrotate /etc/pihole/logrotate
+    install -D -m 644 -T "${PI_HOLE_LOCAL_REPO}"/advanced/Templates/logrotate ${target}
     # Different operating systems have different user / group
     # settings for logrotate that makes it impossible to create
     # a static logrotate file that will work with e.g.
@@ -1955,9 +1963,9 @@ installLogrotate() {
     # the local properties of the /var/log directory
     logusergroup="$(stat -c '%U %G' /var/log)"
     # If there is a usergroup for log rotation,
-    if [[ ! -z "${logusergroup}" ]]; then
+    if [[ -n "${logusergroup}" ]]; then
         # replace the line in the logrotate script with that usergroup.
-        sed -i "s/# su #/su ${logusergroup}/g;" /etc/pihole/logrotate
+        sed -i "s/# su #/su ${logusergroup}/g;" ${target}
     fi
     printf "%b  %b %s\\n" "${OVER}" "${TICK}" "${str}"
 }
diff --git a/automated install/uninstall.sh b/automated install/uninstall.sh
index a0d3b108..543ca07a 100755
--- a/automated install/uninstall.sh	
+++ b/automated install/uninstall.sh	
@@ -206,11 +206,7 @@ removeNoPurge() {
 }
 
 ######### SCRIPT ###########
-if command -v vcgencmd &> /dev/null; then
-    echo -e "  ${INFO} All dependencies are safe to remove on Raspbian"
-else
-    echo -e "  ${INFO} Be sure to confirm if any dependencies should not be removed"
-fi
+echo -e "  ${INFO} Be sure to confirm if any dependencies should not be removed"
 while true; do
     echo -e "  ${INFO} ${COL_YELLOW}The following dependencies may have been added by the Pi-hole install:"
     echo -n "    "
diff --git a/gravity.sh b/gravity.sh
index 24a41c48..7ba443d8 100755
--- a/gravity.sh
+++ b/gravity.sh
@@ -73,6 +73,8 @@ fi
 # have changed
 gravityDBfile="${GRAVITYDB}"
 gravityTEMPfile="${GRAVITYDB}_temp"
+gravityDIR="$(dirname -- "${gravityDBfile}")"
+gravityOLDfile="${gravityDIR}/gravity_old.db"
 
 if [[ -z "${BLOCKINGMODE}" ]] ; then
   BLOCKINGMODE="NULL"
@@ -123,8 +125,19 @@ gravity_swap_databases() {
   fi
   echo -e "${OVER}  ${TICK} ${str}"
 
-  # Swap databases and remove old database
-  rm "${gravityDBfile}"
+  # Swap databases and remove or conditionally rename old database
+  # Number of available blocks on disk
+  availableBlocks=$(stat -f --format "%a" "${gravityDIR}")
+  # Number of blocks, used by gravity.db
+  gravityBlocks=$(stat --format "%b" ${gravityDBfile})
+  # Only keep the old database if available disk space is at least twice the size of the existing gravity.db.
+  # Better be safe than sorry...
+  if [ "${availableBlocks}" -gt "$(("${gravityBlocks}" * 2))" ] && [ -f "${gravityDBfile}" ]; then
+    echo -e "  ${TICK} The old database remains available."
+    mv "${gravityDBfile}" "${gravityOLDfile}"
+  else
+    rm "${gravityDBfile}"
+  fi
   mv "${gravityTEMPfile}" "${gravityDBfile}"
 }
 
@@ -890,6 +903,11 @@ for var in "$@"; do
   esac
 done
 
+# Remove OLD (backup) gravity file, if it exists
+if [[ -f "${gravityOLDfile}" ]]; then
+  rm "${gravityOLDfile}"
+fi
+
 # Trap Ctrl-C
 gravity_Trap
 
diff --git a/manpages/pihole.8 b/manpages/pihole.8
index 4ba0e0f7..aaaa8d7e 100644
--- a/manpages/pihole.8
+++ b/manpages/pihole.8
@@ -56,7 +56,7 @@ Available commands and options:
 
 \fB-w, whitelist\fR [options] [<domain1> <domain2 ...>]
 .br
-    Adds or removes specified domain or domains tho the Whitelist
+    Adds or removes specified domain or domains to the Whitelist
 .br
 
 \fB-b, blacklist\fR [options] [<domain1> <domain2 ...>]
diff --git a/pihole b/pihole
index f8085c8e..58ec385a 100755
--- a/pihole
+++ b/pihole
@@ -370,7 +370,7 @@ tailFunc() {
   # Color blocklist/blacklist/wildcard entries as red
   # Color A/AAAA/DHCP strings as white
   # Color everything else as gray
-  tail -f /var/log/pihole.log | sed -E \
+  tail -f /var/log/pihole.log | grep --line-buffered "${1}" | sed -E \
     -e "s,($(date +'%b %d ')| dnsmasq\[[0-9]*\]),,g" \
     -e "s,(.*(blacklisted |gravity blocked ).* is (0.0.0.0|::|NXDOMAIN|${IPV4_ADDRESS%/*}|${IPV6_ADDRESS:-NULL}).*),${COL_RED}&${COL_NC}," \
     -e "s,.*(query\\[A|DHCP).*,${COL_NC}&${COL_NC}," \
@@ -456,7 +456,10 @@ Debugging Options:
                         Add '-a' to automatically upload the log to tricorder.pi-hole.net
   -f, flush           Flush the Pi-hole log
   -r, reconfigure     Reconfigure or Repair Pi-hole subsystems
-  -t, tail            View the live output of the Pi-hole log
+  -t, tail [arg]      View the live output of the Pi-hole log.
+                      Add an optional argument to filter the log
+                      (regular expressions are supported)
+
 
 Options:
   -a, admin           Web interface options
@@ -530,7 +533,7 @@ case "${1}" in
   "status"                      ) statusFunc "$2";;
   "restartdns"                  ) restartDNS "$2";;
   "-a" | "admin"                ) webpageFunc "$@";;
-  "-t" | "tail"                 ) tailFunc;;
+  "-t" | "tail"                 ) tailFunc "$2";;
   "checkout"                    ) piholeCheckoutFunc "$@";;
   "tricorder"                   ) tricorderFunc;;
   "updatechecker"               ) updateCheckFunc "$@";;
diff --git a/test/test_automated_install.py b/test/test_automated_install.py
index 44624082..0849aa9a 100644
--- a/test/test_automated_install.py
+++ b/test/test_automated_install.py
@@ -597,3 +597,42 @@ def test_os_check_passes(Pihole):
     ''')
     expected_stdout = 'Supported OS detected'
     assert expected_stdout in detectOS.stdout
+
+
+def test_package_manager_has_installer_deps(Pihole):
+    ''' Confirms OS is able to install the required packages for the installer'''
+    mock_command('whiptail', {'*': ('', '0')}, Pihole)
+    output = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    install_dependent_packages ${INSTALLER_DEPS[@]}
+    ''')
+
+    assert 'No package' not in output.stdout  # centos7 still exits 0...
+    assert output.rc == 0
+
+
+def test_package_manager_has_pihole_deps(Pihole):
+    ''' Confirms OS is able to install the required packages for Pi-hole '''
+    mock_command('whiptail', {'*': ('', '0')}, Pihole)
+    output = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    install_dependent_packages ${PIHOLE_DEPS[@]}
+    ''')
+
+    assert 'No package' not in output.stdout  # centos7 still exits 0...
+    assert output.rc == 0
+
+
+def test_package_manager_has_web_deps(Pihole):
+    ''' Confirms OS is able to install the required packages for web '''
+    mock_command('whiptail', {'*': ('', '0')}, Pihole)
+    output = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    install_dependent_packages ${PIHOLE_WEB_DEPS[@]}
+    ''')
+
+    assert 'No package' not in output.stdout  # centos7 still exits 0...
+    assert output.rc == 0