Preflight disk space before Pulse updates

install.sh

@@ -31,6 +31,8 @@ CONTAINER_CREATED_FOR_CLEANUP=false
 BUILD_FROM_SOURCE_MARKER="$INSTALL_DIR/BUILD_FROM_SOURCE"
 DETECTED_CTID=""
 STOPPED_PULSE_SERVICE=""
+UPDATE_MIN_TEMP_FREE_BYTES=$((900 * 1024 * 1024))
+UPDATE_MIN_INSTALL_FREE_BYTES=$((256 * 1024 * 1024))
 
 # Installer version - the major version this script is bundled with
 INSTALLER_MAJOR_VERSION=5
@@ -42,6 +44,97 @@ AUTO_NODE_REGISTER_ERROR=""
 DEBIAN_TEMPLATE_FALLBACK="debian-12-standard_12.12-1_amd64.tar.zst"
 DEBIAN_TEMPLATE=""
 
+bytes_to_human() {
+    local bytes="${1:-0}"
+
+    if [[ ! "$bytes" =~ ^[0-9]+$ ]]; then
+        printf '%s\n' "$bytes"
+        return 0
+    fi
+
+    local units=("B" "KB" "MB" "GB" "TB")
+    local value="$bytes"
+    local unit_index=0
+
+    while (( value >= 1024 && unit_index < ${#units[@]} - 1 )); do
+        value=$((value / 1024))
+        ((unit_index += 1))
+    done
+
+    printf '%s%s\n' "$value" "${units[$unit_index]}"
+}
+
+get_available_bytes_for_path() {
+    local path="$1"
+    local available_kb=""
+
+    available_kb=$(df -Pk "$path" 2>/dev/null | awk 'NR==2 {print $4}')
+    if [[ ! "$available_kb" =~ ^[0-9]+$ ]]; then
+        return 1
+    fi
+
+    printf '%s\n' $((available_kb * 1024))
+}
+
+get_filesystem_device_for_path() {
+    local path="$1"
+    local filesystem=""
+
+    filesystem=$(df -Pk "$path" 2>/dev/null | awk 'NR==2 {print $1}')
+    if [[ -z "$filesystem" ]]; then
+        return 1
+    fi
+
+    printf '%s\n' "$filesystem"
+}
+
+ensure_update_disk_headroom() {
+    local temp_path="${1:-/tmp}"
+    local install_path="${2:-$INSTALL_DIR}"
+    local temp_fs=""
+    local install_fs=""
+    local temp_free_bytes=""
+    local install_free_bytes=""
+    local combined_required_bytes=$((UPDATE_MIN_TEMP_FREE_BYTES + UPDATE_MIN_INSTALL_FREE_BYTES))
+
+    temp_fs=$(get_filesystem_device_for_path "$temp_path" 2>/dev/null || true)
+    install_fs=$(get_filesystem_device_for_path "$install_path" 2>/dev/null || true)
+    temp_free_bytes=$(get_available_bytes_for_path "$temp_path" 2>/dev/null || true)
+    install_free_bytes=$(get_available_bytes_for_path "$install_path" 2>/dev/null || true)
+
+    if [[ -z "$temp_free_bytes" || -z "$install_free_bytes" ]]; then
+        print_warn "Could not determine available disk space for the update preflight; continuing anyway"
+        return 0
+    fi
+
+    if [[ -n "$temp_fs" && "$temp_fs" == "$install_fs" ]]; then
+        if (( temp_free_bytes < combined_required_bytes )); then
+            print_error "Not enough free disk space to stage the Pulse update"
+            print_info "The same filesystem backs $temp_path and $install_path"
+            print_info "Available: $(bytes_to_human "$temp_free_bytes"), required: $(bytes_to_human "$combined_required_bytes")"
+            print_info "Free disk space and retry the update"
+            return 1
+        fi
+        return 0
+    fi
+
+    if (( temp_free_bytes < UPDATE_MIN_TEMP_FREE_BYTES )); then
+        print_error "Not enough free disk space in $temp_path to stage the Pulse update"
+        print_info "Available: $(bytes_to_human "$temp_free_bytes"), required: $(bytes_to_human "$UPDATE_MIN_TEMP_FREE_BYTES")"
+        print_info "Free disk space under $temp_path and retry the update"
+        return 1
+    fi
+
+    if (( install_free_bytes < UPDATE_MIN_INSTALL_FREE_BYTES )); then
+        print_error "Not enough free disk space in $install_path to apply the Pulse update"
+        print_info "Available: $(bytes_to_human "$install_free_bytes"), required: $(bytes_to_human "$UPDATE_MIN_INSTALL_FREE_BYTES")"
+        print_info "Free disk space under $install_path and retry the update"
+        return 1
+    fi
+
+    return 0
+}
+
 get_latest_release_from_redirect() {
     # Follow the GitHub "latest" redirect and extract the tag in a way that
     # tolerates intermediate redirects that omit /tag/ (issue #698).
@@ -2604,6 +2697,10 @@ download_pulse() {
 
         rm -f "$BUILD_FROM_SOURCE_MARKER"
 
+        if ! ensure_update_disk_headroom "/tmp" "$INSTALL_DIR"; then
+            exit 1
+        fi
+
         EXISTING_SERVICE=$(detect_service_name)
         stop_pulse_service_for_update "$EXISTING_SERVICE" || true
 

internal/updates/adapter_installsh.go

@@ -59,7 +59,7 @@ func (a *InstallShAdapter) PrepareUpdate(ctx context.Context, request UpdateRequ
 		Prerequisites: []string{
 			"Root access (sudo)",
 			"Internet connection",
-			"At least 100MB free disk space",
+			"About 1.2GB free disk space for update staging",
 		},
 	}
 

scripts/tests/test-server-install.sh

@@ -42,6 +42,68 @@ test_infer_release_from_archive_name_supports_prerelease() {
   )
 }
 
+test_ensure_update_disk_headroom_fails_when_tmp_and_install_share_full_filesystem() {
+  (
+    load_installer
+
+    UPDATE_MIN_TEMP_FREE_BYTES=$((100 * 1024))
+    UPDATE_MIN_INSTALL_FREE_BYTES=$((80 * 1024))
+
+    print_error() { :; }
+    print_info() { :; }
+    print_warn() { :; }
+    df() {
+      if [[ "$1" == "-Pk" ]]; then
+        case "$2" in
+          /tmp|/opt/pulse)
+            printf 'Filesystem 1024-blocks Used Available Capacity Mounted on\n'
+            printf '/dev/shared 1000 0 150 0%% /\n'
+            return 0
+            ;;
+        esac
+      fi
+      command df "$@"
+    }
+
+    if ensure_update_disk_headroom /tmp /opt/pulse; then
+      echo "ensure_update_disk_headroom unexpectedly passed on a shared full filesystem" >&2
+      return 1
+    fi
+  )
+}
+
+test_ensure_update_disk_headroom_accepts_separate_filesystems_with_sufficient_space() {
+  (
+    load_installer
+
+    UPDATE_MIN_TEMP_FREE_BYTES=$((100 * 1024))
+    UPDATE_MIN_INSTALL_FREE_BYTES=$((80 * 1024))
+
+    print_error() { :; }
+    print_info() { :; }
+    print_warn() { :; }
+    df() {
+      if [[ "$1" == "-Pk" ]]; then
+        case "$2" in
+          /tmp)
+            printf 'Filesystem 1024-blocks Used Available Capacity Mounted on\n'
+            printf '/dev/tmp 1000 0 120 0%% /tmp\n'
+            return 0
+            ;;
+          /opt/pulse)
+            printf 'Filesystem 1024-blocks Used Available Capacity Mounted on\n'
+            printf '/dev/root 1000 0 90 0%% /\n'
+            return 0
+            ;;
+        esac
+      fi
+      command df "$@"
+    }
+
+    ensure_update_disk_headroom /tmp /opt/pulse
+  )
+}
+
 test_download_pulse_installs_from_local_archive_without_network() {
   (
     load_installer
@@ -266,6 +328,8 @@ test_install_additional_agent_binaries_skips_network_when_local_extras_are_missi
 
 main() {
   assert_success "infer_release_from_archive_name parses prerelease tarballs" test_infer_release_from_archive_name_supports_prerelease
+  assert_success "update disk preflight fails on shared low-space filesystems" test_ensure_update_disk_headroom_fails_when_tmp_and_install_share_full_filesystem
+  assert_success "update disk preflight passes on separate filesystems with enough headroom" test_ensure_update_disk_headroom_accepts_separate_filesystems_with_sufficient_space
   assert_success "download_pulse installs from local archive without network" test_download_pulse_installs_from_local_archive_without_network
   assert_success "prefetch helper writes archive path via output variable" test_prefetch_pulse_archive_for_container_sets_output_var
   assert_success "wrong-arch archives fail before replacing the installed binary" test_install_pulse_archive_rejects_mismatched_arch_without_replacing_existing_binary