diff --git a/addons/redis-server-ubuntu.sh b/addons/redis-server-ubuntu.sh
index ecb8c0c968..31b9d58545 100644
--- a/addons/redis-server-ubuntu.sh
+++ b/addons/redis-server-ubuntu.sh
@@ -70,10 +70,9 @@ phpenmod -v "$PHPVER" redis
 install_if_not redis-server
 
 ## Redis performance tweaks ##
-if ! grep -Fxq "vm.overcommit_memory = 1" /etc/sysctl.conf
-then
-    echo 'vm.overcommit_memory = 1' >> /etc/sysctl.conf
-fi
+# /etc/sysctl.conf isn't read at boot on Ubuntu 26.04, so use sysctl.d
+echo 'vm.overcommit_memory = 1' > /etc/sysctl.d/90-redis.conf
+sysctl -w vm.overcommit_memory=1
 
 # Disable THP
 if ! grep -Fxq "never" /sys/kernel/mm/transparent_hugepage/enabled
diff --git a/apps/smbmount.sh b/apps/smbmount.sh
index 4987b09d5b..0274c5111d 100644
--- a/apps/smbmount.sh
+++ b/apps/smbmount.sh
@@ -331,7 +331,7 @@ If you choose 'yes', we will install a needed PHP-plugin, the files_inotify app
 Please note, that this will need around 1 KB additional RAM per folder.
 We will set the max folder variable to 524288 which will be around \
 500 MB of additionally needed RAM if you have so many folders.
-If you have more folders, you will need to raise this value manually inside '/etc/sysctl.conf'.
+If you have more folders, you will need to raise this value manually inside '/etc/sysctl.d/90-inotify.conf'.
 Please also note, that this max folder variable counts for \
 all external storages for which the inotify option gets activated.
 We please you to do the math yourself if the number is high enough for your setup."
@@ -380,11 +380,11 @@ We please you to do the math yourself if the number is high enough for your setu
             # Set fs.inotify.max_user_watches to 524288
             # https://unix.stackexchange.com/questions/13751/kernel-inotify-watch-limit-reached
             # https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers
-            if ! grep -q "fs.inotify.max_user_watches" /etc/sysctl.conf
+            if ! grep -qs "fs.inotify.max_user_watches" /etc/sysctl.d/90-inotify.conf
             then
                 print_text_in_color "$ICyan" "Setting the max folder variable to 524288..."
-                echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
-                sudo sysctl -p
+                echo fs.inotify.max_user_watches=524288 | sudo tee /etc/sysctl.d/90-inotify.conf
+                sudo sysctl -p /etc/sysctl.d/90-inotify.conf
             fi
 
             # Create syslog for files_inotify
diff --git a/lib.sh b/lib.sh
index 16af9f5cc3..9307b76f67 100644
--- a/lib.sh
+++ b/lib.sh
@@ -1762,15 +1762,15 @@ fi
 }
 
 set_max_count() {
-if grep -F 'vm.max_map_count=512000' /etc/sysctl.conf ; then
+# /etc/sysctl.conf isn't read at boot on Ubuntu 26.04, so use sysctl.d
+if grep -Fqs 'vm.max_map_count=512000' /etc/sysctl.d/90-max_map_count.conf ; then
     print_text_in_color "$ICyan" "Max map count already set, skipping..."
 else
     sysctl -w vm.max_map_count=512000
     {
-        echo "###################################################################"
         echo "# Docker ES max virtual memory"
         echo "vm.max_map_count=512000"
-    } >> /etc/sysctl.conf
+    } > /etc/sysctl.d/90-max_map_count.conf
 fi
 }
 
diff --git a/nextcloud_update.sh b/nextcloud_update.sh
index c4ea49416b..a8c829412f 100644
--- a/nextcloud_update.sh
+++ b/nextcloud_update.sh
@@ -529,6 +529,12 @@ else
     fi
 fi
 
+# /etc/sysctl.conf isn't read at boot on Ubuntu 26.04, but older scripts saved settings there
+if [ -f /etc/sysctl.conf ] && [ ! -e /etc/sysctl.d/99-sysctl.conf ]
+then
+    ln -s ../sysctl.conf /etc/sysctl.d/99-sysctl.conf
+fi
+
 # Remove APCu https://github.com/nextcloud/vm/issues/2039
 if is_this_installed "php$PHPVER"-dev
 then
diff --git a/not-supported/smbserver.sh b/not-supported/smbserver.sh
index 4f04f389f2..d540717132 100644
--- a/not-supported/smbserver.sh
+++ b/not-supported/smbserver.sh
@@ -898,7 +898,7 @@ If you choose 'yes', we will install a needed PHP-plugin, the files_inotify app
 Please note, that this will need around 1 KB additional RAM per folder.
 We will set the max folder variable to 524288 which will be around 500 MB \
 of additionally needed RAM if you have so many folders.
-If you have more folders, you will need to raise this value manually inside '/etc/sysctl.conf'.
+If you have more folders, you will need to raise this value manually inside '/etc/sysctl.d/90-inotify.conf'.
 Please also note, that this max folder variable counts for all \
 external storages for which the inotify option gets activated.
 We please you to do the math yourself if the number is high enough for your setup."
@@ -928,11 +928,11 @@ We please you to do the math yourself if the number is high enough for your setu
     # Set fs.inotify.max_user_watches to 524288
     # https://unix.stackexchange.com/questions/13751/kernel-inotify-watch-limit-reached
     # https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers
-    if ! grep -q "fs.inotify.max_user_watches" /etc/sysctl.conf
+    if ! grep -qs "fs.inotify.max_user_watches" /etc/sysctl.d/90-inotify.conf
     then
         print_text_in_color "$ICyan" "Setting the max folder variable to 524288..."
-        echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
-        sudo sysctl -p
+        echo fs.inotify.max_user_watches=524288 | sudo tee /etc/sysctl.d/90-inotify.conf
+        sudo sysctl -p /etc/sysctl.d/90-inotify.conf
     fi
 
     # Create syslog for files_inotify