diff --git a/app/Actions/Server/UpdateCoolify.php b/app/Actions/Server/UpdateCoolify.php
index 3c60c34379..7011ec5429 100644
--- a/app/Actions/Server/UpdateCoolify.php
+++ b/app/Actions/Server/UpdateCoolify.php
@@ -3,6 +3,8 @@
 namespace App\Actions\Server;
 
 use App\Models\Server;
+use App\Notifications\Server\UpgradeSkippedLowDiskSpace;
+use App\Services\CoolifyUpgradeDiskSpace;
 use App\Services\CoolifyUpgradeStatus;
 use Illuminate\Support\Facades\Http;
 use Illuminate\Support\Facades\Log;
@@ -19,7 +21,7 @@ class UpdateCoolify
 
     public ?string $currentVersion = null;
 
-    public function handle($manual_update = false)
+    public function handle($manual_update = false, bool $skipDiskSpaceCheck = false)
     {
         if (isDev()) {
             Sleep::for(10)->seconds();
@@ -110,12 +112,16 @@ class UpdateCoolify
             );
         }
 
-        $this->update();
+        if (! $skipDiskSpaceCheck && ! $this->ensureEnoughDiskSpace($manual_update)) {
+            return;
+        }
+
+        $this->update($skipDiskSpaceCheck);
         $settings->new_version_available = false;
         $settings->save();
     }
 
-    private function update()
+    private function update(bool $skipDiskSpaceCheck)
     {
         $this->ensureNoUpgradeIsRunning();
 
@@ -123,15 +129,54 @@ class UpdateCoolify
         $upgradeScriptUrl = config('constants.coolify.upgrade_script_url');
         $registryUrl = coolifyRegistryUrl();
 
+        $upgradeCommand = 'bash /data/coolify/source/upgrade.sh '.
+            escapeshellarg($this->latestVersion).' '.
+            escapeshellarg($latestHelperImageVersion).' '.
+            escapeshellarg($registryUrl);
+        if ($skipDiskSpaceCheck) {
+            // Arguments 4 and 5: do not skip the backup, skip the disk space check.
+            $upgradeCommand .= " 'false' 'true'";
+        }
+
         remote_process([
             "curl -fsSL {$upgradeScriptUrl} -o /data/coolify/source/upgrade.sh",
-            'bash /data/coolify/source/upgrade.sh '.
-                escapeshellarg($this->latestVersion).' '.
-                escapeshellarg($latestHelperImageVersion).' '.
-                escapeshellarg($registryUrl),
+            $upgradeCommand,
         ], $this->server);
     }
 
+    /**
+     * Automatic updates are skipped and the team is notified. Manual updates fail with an error.
+     */
+    private function ensureEnoughDiskSpace(bool $manualUpdate): bool
+    {
+        $availableGb = $this->availableDiskSpaceGb();
+        if (! CoolifyUpgradeDiskSpace::isLow($availableGb)) {
+            return true;
+        }
+
+        Log::warning('Upgrade skipped because of low disk space', [
+            'target_version' => $this->latestVersion,
+            'available_gb' => $availableGb,
+            'required_gb' => CoolifyUpgradeDiskSpace::REQUIRED_GB,
+            'manual_update' => $manualUpdate,
+        ]);
+
+        if ($manualUpdate) {
+            throw new \Exception(
+                "Not enough free disk space to upgrade: {$availableGb} GB free, ".CoolifyUpgradeDiskSpace::REQUIRED_GB.' GB required.'
+            );
+        }
+
+        $this->server->team?->notify(new UpgradeSkippedLowDiskSpace($this->server, $this->latestVersion, $availableGb));
+
+        return false;
+    }
+
+    protected function availableDiskSpaceGb(): ?float
+    {
+        return app(CoolifyUpgradeDiskSpace::class)->availableGb($this->server);
+    }
+
     private function ensureNoUpgradeIsRunning(): void
     {
         $status = $this->readUpgradeStatus();
diff --git a/app/Livewire/Upgrade.php b/app/Livewire/Upgrade.php
index 75d9b32b3e..62d922e4f6 100644
--- a/app/Livewire/Upgrade.php
+++ b/app/Livewire/Upgrade.php
@@ -3,8 +3,10 @@
 namespace App\Livewire;
 
 use App\Actions\Server\UpdateCoolify;
+use App\Jobs\DockerCleanupJob;
 use App\Models\InstanceSettings;
 use App\Models\Server;
+use App\Services\CoolifyUpgradeDiskSpace;
 use App\Services\CoolifyUpgradeStatus;
 use Livewire\Component;
 
@@ -62,19 +64,30 @@ class Upgrade extends Component
         $this->isUpgradeAvailable = $hasNewerVersion && $newVersionAvailable;
     }
 
-    public function upgrade()
+    /**
+     * Start the upgrade. Without $skipDiskSpaceCheck, the upgrade does not start when the disk is almost full.
+     *
+     * @return array{status: 'started'|'low_disk_space', available_gb?: float|null, required_gb?: int}|null
+     */
+    public function upgrade(bool $skipDiskSpaceCheck = false)
     {
         try {
             if (! isInstanceAdmin()) {
                 abort(403);
             }
             if ($this->updateInProgress) {
-                return;
+                return null;
+            }
+            if (! $skipDiskSpaceCheck) {
+                $diskSpace = $this->checkDiskSpace();
+                if ($diskSpace['status'] === 'low_disk_space') {
+                    return $diskSpace;
+                }
             }
             $this->updateInProgress = true;
-            dispatch(function () {
+            dispatch(function () use ($skipDiskSpaceCheck) {
                 try {
-                    UpdateCoolify::run(manual_update: true);
+                    UpdateCoolify::run(manual_update: true, skipDiskSpaceCheck: $skipDiskSpaceCheck);
                 } catch (\Throwable $e) {
                     report($e);
                 }
@@ -85,7 +98,50 @@ class Upgrade extends Component
                 'resource' => 'instance',
                 'from_version' => config('constants.coolify.version'),
                 'to_version' => get_latest_version_of_coolify(),
+                'skip_disk_space_check' => $skipDiskSpaceCheck,
             ]);
+
+            return ['status' => 'started'];
+        } catch (\Throwable $e) {
+            return handleError($e, $this);
+        }
+    }
+
+    /**
+     * @return array{status: 'low_disk_space'|'ok', available_gb: float|null, required_gb: int}
+     */
+    public function checkDiskSpace(): array
+    {
+        if (! isInstanceAdmin()) {
+            abort(403);
+        }
+
+        $server = Server::find(0);
+        $availableGb = $server ? app(CoolifyUpgradeDiskSpace::class)->availableGb($server) : null;
+
+        return [
+            'status' => CoolifyUpgradeDiskSpace::isLow($availableGb) ? 'low_disk_space' : 'ok',
+            'available_gb' => $availableGb,
+            'required_gb' => CoolifyUpgradeDiskSpace::REQUIRED_GB,
+        ];
+    }
+
+    public function runDockerCleanup()
+    {
+        try {
+            if (! isInstanceAdmin()) {
+                abort(403);
+            }
+            $server = Server::findOrFail(0);
+            DockerCleanupJob::dispatch($server, true);
+            auditLog('ui.server.docker_cleanup_started', [
+                'team_id' => $server->team_id,
+                'server_uuid' => $server->uuid,
+                'server_name' => $server->name,
+                'delete_unused_volumes' => false,
+                'delete_unused_networks' => false,
+            ]);
+            $this->dispatch('success', 'Docker cleanup started. When it is done, click "Check again".');
         } catch (\Throwable $e) {
             return handleError($e, $this);
         }
diff --git a/app/Notifications/Server/UpgradeSkippedLowDiskSpace.php b/app/Notifications/Server/UpgradeSkippedLowDiskSpace.php
new file mode 100644
index 0000000000..4a015009b6
--- /dev/null
+++ b/app/Notifications/Server/UpgradeSkippedLowDiskSpace.php
@@ -0,0 +1,121 @@
+<?php
+
+namespace App\Notifications\Server;
+
+use App\Contracts\ThrottledNotification;
+use App\Models\Server;
+use App\Notifications\CustomEmailNotification;
+use App\Notifications\Dto\DiscordMessage;
+use App\Notifications\Dto\PushoverMessage;
+use App\Notifications\Dto\SlackMessage;
+use App\Services\CoolifyUpgradeDiskSpace;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Notifications\Messages\MailMessage;
+
+class UpgradeSkippedLowDiskSpace extends CustomEmailNotification implements ThrottledNotification
+{
+    public int $requiredGb = CoolifyUpgradeDiskSpace::REQUIRED_GB;
+
+    public function __construct(public Server $server, public string $version, public float $availableGb)
+    {
+        $this->onQueue('high');
+    }
+
+    public function via(object $notifiable): array
+    {
+        return $notifiable->getEnabledChannels('server_disk_usage');
+    }
+
+    public function throttleSubject(): ?Model
+    {
+        return $this->server;
+    }
+
+    public function throttleIntervalMinutes(): int
+    {
+        return 24 * 60;
+    }
+
+    private function cleanupUrl(): string
+    {
+        return base_url().'/server/'.$this->server->uuid.'/docker-cleanup';
+    }
+
+    public function toMail(): MailMessage
+    {
+        $mail = new MailMessage;
+        $mail->subject("Coolify: Automatic update to {$this->version} skipped, not enough free disk space");
+        $mail->view('emails.upgrade-skipped-low-disk-space', [
+            'version' => $this->version,
+            'available_gb' => $this->availableGb,
+            'required_gb' => $this->requiredGb,
+            'cleanup_url' => $this->cleanupUrl(),
+        ]);
+
+        return $mail;
+    }
+
+    public function toDiscord(): DiscordMessage
+    {
+        $message = new DiscordMessage(
+            title: ':warning: Automatic update skipped',
+            description: "Coolify did not update to {$this->version} because the server does not have enough free disk space.",
+            color: DiscordMessage::warningColor(),
+            isCritical: true,
+        );
+
+        $message->addField('Free', "{$this->availableGb} GB", true);
+        $message->addField('Required', "{$this->requiredGb} GB", true);
+        $message->addField('What to do?', '[Docker cleanup]('.$this->cleanupUrl().')', true);
+
+        return $message;
+    }
+
+    public function toTelegram(): array
+    {
+        return [
+            'message' => "Coolify: Automatic update to {$this->version} skipped.\nFree disk space: {$this->availableGb} GB. Required: {$this->requiredGb} GB.\nFree up disk space (for example, run a Docker cleanup): {$this->cleanupUrl()}",
+        ];
+    }
+
+    public function toPushover(): PushoverMessage
+    {
+        return new PushoverMessage(
+            title: 'Automatic update skipped',
+            level: 'warning',
+            message: "Coolify did not update to {$this->version} because the server does not have enough free disk space.<br/><br/><b>Free:</b> {$this->availableGb} GB.<br/><b>Required:</b> {$this->requiredGb} GB.",
+            buttons: [
+                'Docker cleanup' => $this->cleanupUrl(),
+            ],
+        );
+    }
+
+    public function toSlack(): SlackMessage
+    {
+        $description = "Coolify did not update to {$this->version} because the server does not have enough free disk space.\n";
+        $description .= "Free: {$this->availableGb} GB\n";
+        $description .= "Required: {$this->requiredGb} GB\n\n";
+        $description .= 'Free up disk space (for example, run a Docker cleanup): '.$this->cleanupUrl();
+
+        return new SlackMessage(
+            title: 'Automatic update skipped',
+            description: $description,
+            color: SlackMessage::warningColor()
+        );
+    }
+
+    public function toWebhook(): array
+    {
+        return [
+            'success' => false,
+            'message' => 'Automatic update skipped, not enough free disk space',
+            'event' => 'upgrade_skipped_low_disk_space',
+            'version' => $this->version,
+            'server_name' => $this->server->name,
+            'server_uuid' => $this->server->uuid,
+            'available_gb' => $this->availableGb,
+            'required_gb' => $this->requiredGb,
+            'url' => $this->cleanupUrl(),
+        ];
+    }
+}
diff --git a/app/Services/CoolifyUpgradeDiskSpace.php b/app/Services/CoolifyUpgradeDiskSpace.php
new file mode 100644
index 0000000000..a0ec794f21
--- /dev/null
+++ b/app/Services/CoolifyUpgradeDiskSpace.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\Server;
+
+/**
+ * An upgrade pulls new images and recreates the Coolify containers. When the disk becomes full
+ * during an upgrade, Coolify can stop working (for example, an empty config cache file).
+ */
+class CoolifyUpgradeDiskSpace
+{
+    public const REQUIRED_GB = 5;
+
+    public const UPGRADE_PATHS = ['/data/coolify'];
+
+    public const DEFAULT_DOCKER_ROOT_DIR = '/var/lib/docker';
+
+    /**
+     * Free space in GB on the Docker data directory and /data/coolify. The smaller value is returned.
+     * Returns null when the free space cannot be measured, so an unknown value never blocks an upgrade.
+     */
+    public function availableGb(Server $server): ?float
+    {
+        $dockerRootDir = trim((string) instant_remote_process(
+            ["docker info --format '{{.DockerRootDir}}' 2>/dev/null || true"],
+            $server,
+            false
+        ));
+
+        $paths = collect([...self::UPGRADE_PATHS, $dockerRootDir ?: self::DEFAULT_DOCKER_ROOT_DIR])
+            ->map(fn (string $path) => escapeshellarg($path))
+            ->implode(' ');
+
+        $output = instant_remote_process(["df -Pk {$paths} 2>/dev/null || true"], $server, false);
+
+        return self::parseDfOutput((string) $output);
+    }
+
+    /**
+     * Read the smallest "Available" column (in 1K blocks) from `df -Pk` output and return it in GB.
+     */
+    public static function parseDfOutput(string $output): ?float
+    {
+        $availableKb = collect(preg_split('/\R/', trim($output)))
+            ->skip(1)
+            ->map(fn (string $line) => preg_split('/\s+/', trim($line))[3] ?? null)
+            ->filter(fn (?string $value) => $value !== null && ctype_digit($value))
+            ->map(fn (string $value) => (int) $value)
+            ->min();
+
+        if ($availableKb === null) {
+            return null;
+        }
+
+        return round($availableKb / 1024 / 1024, 1);
+    }
+
+    public static function isLow(?float $availableGb): bool
+    {
+        return $availableGb !== null && $availableGb < self::REQUIRED_GB;
+    }
+}
diff --git a/resources/views/emails/upgrade-skipped-low-disk-space.blade.php b/resources/views/emails/upgrade-skipped-low-disk-space.blade.php
new file mode 100644
index 0000000000..fe9ecac38f
--- /dev/null
+++ b/resources/views/emails/upgrade-skipped-low-disk-space.blade.php
@@ -0,0 +1,5 @@
+<x-emails.layout>
+Coolify did not update to {{ $version }} because the server does not have enough free disk space ({{ $available_gb }} GB free, {{ $required_gb }} GB required).
+
+Free up disk space, for example with a [Docker cleanup]({{ $cleanup_url }}). The next automatic update will try again.
+</x-emails.layout>
diff --git a/resources/views/livewire/upgrade.blade.php b/resources/views/livewire/upgrade.blade.php
index 2af8873207..aa4234474c 100644
--- a/resources/views/livewire/upgrade.blade.php
+++ b/resources/views/livewire/upgrade.blade.php
@@ -137,8 +137,53 @@
                                 </div>
                             </template>
 
+                            {{-- Low Disk Space View --}}
+                            <template x-if="!showProgress && lowDiskSpace">
+                                <div class="flex flex-col gap-4">
+                                    <x-callout type="danger" title="Not enough free disk space">
+                                        <p>
+                                            The server has <span class="font-semibold" x-text="availableGb + ' GB'"></span> free.
+                                            The upgrade needs at least <span class="font-semibold" x-text="requiredGb + ' GB'"></span>.
+                                            If the disk becomes full during the upgrade, Coolify can stop working.
+                                        </p>
+                                    </x-callout>
+
+                                    <p class="text-[12px] leading-5" style="color: var(--coollabs-subtle)">
+                                        Run a Docker cleanup to remove unused images, containers, and build cache, then check again.
+                                    </p>
+
+                                    <template x-if="confirmOverride">
+                                        <x-callout type="warning" title="Upgrade anyway?">
+                                            <p>Only continue if you are sure that the upgrade has enough disk space.</p>
+                                        </x-callout>
+                                    </template>
+
+                                    <div
+                                        class="flex flex-wrap items-center justify-end gap-2 border-t border-neutral-200 pt-4 dark:border-white/[0.08]">
+                                        <template x-if="!confirmOverride">
+                                            <x-forms.button @click="confirmOverride = true" type="button">
+                                                Upgrade anyway
+                                            </x-forms.button>
+                                        </template>
+                                        <template x-if="confirmOverride">
+                                            <x-forms.button @click="confirmed(true)" type="button"
+                                                x-bind:disabled="checkingDiskSpace">
+                                                Yes, upgrade anyway
+                                            </x-forms.button>
+                                        </template>
+                                        <x-forms.button @click="$wire.runDockerCleanup()" type="button">
+                                            Run Docker cleanup
+                                        </x-forms.button>
+                                        <x-forms.button @click="checkDiskSpaceAgain()" isHighlighted type="button"
+                                            x-bind:disabled="checkingDiskSpace">
+                                            <span x-text="checkingDiskSpace ? 'Checking…' : 'Check again'"></span>
+                                        </x-forms.button>
+                                    </div>
+                                </div>
+                            </template>
+
                             {{-- Confirmation View --}}
-                            <template x-if="!showProgress">
+                            <template x-if="!showProgress && !lowDiskSpace">
                                 <div class="flex flex-col gap-4">
                                     <x-callout type="warning" title="Caution">
                                         <p>Any deployments running during the update process will fail.</p>
@@ -160,8 +205,9 @@
                                                 Simulate
                                             </x-forms.button>
                                         </template>
-                                        <x-forms.button @click="confirmed" isHighlighted type="button">
-                                            Upgrade now
+                                        <x-forms.button @click="confirmed()" isHighlighted type="button"
+                                            x-bind:disabled="checkingDiskSpace">
+                                            <span x-text="checkingDiskSpace ? 'Checking disk space…' : 'Upgrade now'"></span>
                                         </x-forms.button>
                                     </div>
                                 </div>
@@ -202,6 +248,11 @@
             instanceWentDown: false,
             devMode: config.devMode || false,
             simulationInterval: null,
+            lowDiskSpace: false,
+            availableGb: null,
+            requiredGb: null,
+            confirmOverride: false,
+            checkingDiskSpace: false,
 
             simulateUpgrade() {
                 if (!this.devMode) return;
@@ -234,13 +285,30 @@
                 }, 2000);
             },
 
-            confirmed() {
+            async confirmed(skipDiskSpaceCheck = false) {
+                if (this.checkingDiskSpace) return;
+                this.checkingDiskSpace = true;
+                let result;
+                try {
+                    // Trigger server-side upgrade script via Livewire. It does not start when the disk is almost full.
+                    result = await this.$wire.upgrade(skipDiskSpaceCheck);
+                } finally {
+                    this.checkingDiskSpace = false;
+                }
+                if (result?.status === 'low_disk_space') {
+                    this.lowDiskSpace = true;
+                    this.availableGb = result.available_gb;
+                    this.requiredGb = result.required_gb;
+                    return;
+                }
+                if (result?.status !== 'started') return;
+
+                this.lowDiskSpace = false;
+                this.confirmOverride = false;
                 this.showProgress = true;
                 this.currentStep = 1;
                 this.currentStatus = 'Starting upgrade...';
                 this.startTimer();
-                // Trigger server-side upgrade script via Livewire
-                this.$wire.$call('upgrade');
                 // Start client-side status polling
                 this.upgrade();
                 // Prevent accidental navigation during upgrade
@@ -251,6 +319,22 @@
                 window.addEventListener('beforeunload', this.beforeUnloadHandler);
             },
 
+            async checkDiskSpaceAgain() {
+                if (this.checkingDiskSpace) return;
+                this.checkingDiskSpace = true;
+                try {
+                    const result = await this.$wire.checkDiskSpace();
+                    this.availableGb = result.available_gb;
+                    this.requiredGb = result.required_gb;
+                    this.lowDiskSpace = result.status === 'low_disk_space';
+                    if (!this.lowDiskSpace) {
+                        this.confirmOverride = false;
+                    }
+                } finally {
+                    this.checkingDiskSpace = false;
+                }
+            },
+
             startTimer() {
                 this.startTime = Date.now();
                 this.elapsedInterval = setInterval(() => {
diff --git a/scripts/upgrade.sh b/scripts/upgrade.sh
index c2bcabc3f7..6afbdb7176 100644
--- a/scripts/upgrade.sh
+++ b/scripts/upgrade.sh
@@ -13,6 +13,8 @@ else
     REGISTRY_URL="docker.io"
 fi
 SKIP_BACKUP=${4:-false}
+SKIP_DISK_SPACE_CHECK=${5:-false}
+REQUIRED_DISK_SPACE_GB=5
 STATUS_FILE="/data/coolify/source/.upgrade-status"
 
 DATE=$(date +%Y-%m-%d-%H-%M-%S)
@@ -53,6 +55,24 @@ echo "Helper Version: ${LATEST_HELPER_VERSION}" >>"$LOGFILE"
 echo "Registry URL: ${REGISTRY_URL}" >>"$LOGFILE"
 echo "============================================================" >>"$LOGFILE"
 
+# Stop before anything changes when the disk is almost full.
+# A full disk during the upgrade can leave Coolify broken.
+if [ "$SKIP_DISK_SPACE_CHECK" != "true" ]; then
+    DOCKER_ROOT_DIR=$(docker info --format '{{.DockerRootDir}}' 2>/dev/null)
+    AVAILABLE_KB=$(df -Pk /data/coolify "${DOCKER_ROOT_DIR:-/var/lib/docker}" 2>/dev/null | awk 'NR>1 && $4 ~ /^[0-9]+$/ {print $4}' | sort -n | head -n1)
+    if [ -n "$AVAILABLE_KB" ] && [ "$AVAILABLE_KB" -lt $((REQUIRED_DISK_SPACE_GB * 1024 * 1024)) ]; then
+        AVAILABLE_GB=$(awk -v kb="$AVAILABLE_KB" 'BEGIN {printf "%.1f", kb / 1024 / 1024}')
+        log "ERROR: Not enough free disk space: ${AVAILABLE_GB} GB free, ${REQUIRED_DISK_SPACE_GB} GB required"
+        write_status "error" "Not enough free disk space: ${AVAILABLE_GB} GB free, ${REQUIRED_DISK_SPACE_GB} GB required. Free up disk space and try again."
+        echo "     ERROR: Not enough free disk space: ${AVAILABLE_GB} GB free, ${REQUIRED_DISK_SPACE_GB} GB required."
+        echo "     Free up disk space (for example: docker system prune) and try again."
+        exit 1
+    fi
+    log "Disk space check passed (${AVAILABLE_KB:-unknown} KB free)"
+else
+    log "Disk space check skipped"
+fi
+
 log_section "Step 1/6: Downloading configuration files"
 write_status "1" "Downloading configuration files"
 echo "1/6 Downloading latest configuration files..."
diff --git a/tests/Feature/UpgradeComponentTest.php b/tests/Feature/UpgradeComponentTest.php
index d3379e78c8..fecfef84f7 100644
--- a/tests/Feature/UpgradeComponentTest.php
+++ b/tests/Feature/UpgradeComponentTest.php
@@ -1,9 +1,15 @@
 <?php
 
+use App\Jobs\DockerCleanupJob;
 use App\Livewire\Upgrade;
 use App\Models\InstanceSettings;
+use App\Models\Server;
+use App\Models\Team;
+use App\Models\User;
+use App\Services\CoolifyUpgradeDiskSpace;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\Queue;
 use Livewire\Livewire;
 
 uses(RefreshDatabase::class);
@@ -98,3 +104,82 @@ it('clears stale upgrade availability when current version is newer than cached
 
     expect((bool) InstanceSettings::findOrFail(0)->new_version_available)->toBeFalse();
 });
+
+function upgradeComponentTestLoginToRootTeam(string $role, ?float $availableGb = null): void
+{
+    config(['constants.coolify.version' => '4.0.0-beta.998']);
+    Cache::put('coolify:versions:all', ['coolify' => ['v4' => ['version' => '4.0.0-beta.999']]], 3600);
+    InstanceSettings::forceCreate(['id' => 0, 'new_version_available' => true]);
+    $rootTeam = Team::factory()->create(['id' => 0]);
+    Server::forceCreate([
+        'id' => 0,
+        'name' => 'localhost',
+        'ip' => '127.0.0.1',
+        'user' => 'root',
+        'team_id' => 0,
+        'private_key_id' => 1,
+    ]);
+
+    $user = User::factory()->create();
+    $rootTeam->members()->attach($user->id, ['role' => $role]);
+    test()->actingAs($user);
+    session(['currentTeam' => ['id' => 0]]);
+
+    test()->mock(CoolifyUpgradeDiskSpace::class)
+        ->shouldReceive('availableGb')
+        ->andReturn($availableGb);
+}
+
+it('does not start the upgrade when the disk is almost full', function () {
+    upgradeComponentTestLoginToRootTeam('admin', 3.2);
+
+    Livewire::test(Upgrade::class)
+        ->call('upgrade')
+        ->assertReturned(['status' => 'low_disk_space', 'available_gb' => 3.2, 'required_gb' => 5])
+        ->assertSet('updateInProgress', false);
+});
+
+it('starts the upgrade when the disk has enough free space', function () {
+    upgradeComponentTestLoginToRootTeam('admin', 42.0);
+
+    Livewire::test(Upgrade::class)
+        ->call('upgrade')
+        ->assertReturned(['status' => 'started'])
+        ->assertSet('updateInProgress', true);
+});
+
+it('starts the upgrade on a low disk when the admin confirms the override', function () {
+    upgradeComponentTestLoginToRootTeam('admin', 3.2);
+
+    Livewire::test(Upgrade::class)
+        ->call('upgrade', true)
+        ->assertReturned(['status' => 'started'])
+        ->assertSet('updateInProgress', true);
+});
+
+it('starts a docker cleanup on the localhost server for an instance admin', function () {
+    Queue::fake();
+    upgradeComponentTestLoginToRootTeam('admin', 3.2);
+
+    Livewire::test(Upgrade::class)
+        ->call('runDockerCleanup')
+        ->assertDispatched('success');
+
+    Queue::assertPushed(DockerCleanupJob::class, fn (DockerCleanupJob $job) => $job->server->id === 0 && $job->manualCleanup);
+});
+
+it('does not let a root team member check disk space, clean up docker, or upgrade', function () {
+    Queue::fake();
+    upgradeComponentTestLoginToRootTeam('member', 3.2);
+
+    Livewire::test(Upgrade::class)
+        ->call('checkDiskSpace')
+        ->assertForbidden();
+
+    Livewire::test(Upgrade::class)
+        ->call('runDockerCleanup')
+        ->call('upgrade', true)
+        ->assertSet('updateInProgress', false);
+
+    Queue::assertNotPushed(DockerCleanupJob::class);
+});
diff --git a/tests/Unit/CoolifyUpgradeDiskSpaceTest.php b/tests/Unit/CoolifyUpgradeDiskSpaceTest.php
new file mode 100644
index 0000000000..300b0480b2
--- /dev/null
+++ b/tests/Unit/CoolifyUpgradeDiskSpaceTest.php
@@ -0,0 +1,30 @@
+<?php
+
+use App\Services\CoolifyUpgradeDiskSpace;
+
+it('returns the smallest free space of all paths in GB', function () {
+    $output = <<<'DF'
+Filesystem     1024-blocks      Used Available Capacity Mounted on
+/dev/sda1         41152736  20000000  20971520      50% /
+/dev/sdb1        104857600  90000000   4718592      95% /var/lib/docker
+DF;
+
+    expect(CoolifyUpgradeDiskSpace::parseDfOutput($output))->toBe(4.5);
+});
+
+it('returns null when the df output has no free space values', function (string $output) {
+    expect(CoolifyUpgradeDiskSpace::parseDfOutput($output))->toBeNull();
+})->with([
+    'empty' => '',
+    'header only' => 'Filesystem     1024-blocks      Used Available Capacity Mounted on',
+    'error' => "df: /data/coolify: No such file or directory\nPermission denied",
+]);
+
+it('treats only a known value below the minimum as low', function (?float $availableGb, bool $isLow) {
+    expect(CoolifyUpgradeDiskSpace::isLow($availableGb))->toBe($isLow);
+})->with([
+    'unknown' => [null, false],
+    'below minimum' => [4.9, true],
+    'at minimum' => [5.0, false],
+    'above minimum' => [120.3, false],
+]);
diff --git a/tests/Unit/UpdateCoolifyTest.php b/tests/Unit/UpdateCoolifyTest.php
index ddc8c2546b..c15a99fcf6 100644
--- a/tests/Unit/UpdateCoolifyTest.php
+++ b/tests/Unit/UpdateCoolifyTest.php
@@ -6,11 +6,13 @@ use App\Models\InstanceSettings;
 use App\Models\Server;
 use App\Models\Team;
 use App\Models\User;
+use App\Notifications\Server\UpgradeSkippedLowDiskSpace;
 use App\Support\RemoteProcessCommand;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\Http;
 use Illuminate\Support\Facades\Log;
+use Illuminate\Support\Facades\Notification;
 use Illuminate\Support\Facades\Process;
 use Illuminate\Support\Facades\Queue;
 use Illuminate\Support\Once;
@@ -53,6 +55,48 @@ function updateCoolifyTestActionWithStatus(string $status): UpdateCoolify
     };
 }
 
+function updateCoolifyTestActionWithDiskSpace(?float $availableGb): UpdateCoolify
+{
+    return new class($availableGb) extends UpdateCoolify
+    {
+        public function __construct(private ?float $availableGb) {}
+
+        protected function readUpgradeStatus(): ?string
+        {
+            return '';
+        }
+
+        protected function availableDiskSpaceGb(): ?float
+        {
+            return $this->availableGb;
+        }
+    };
+}
+
+function updateCoolifyTestPrepareUpgrade(): void
+{
+    Queue::fake();
+    config([
+        'app.env' => 'testing',
+        'constants.coolify.version' => '4.0.9',
+        'constants.coolify.helper_version' => '1.0.14',
+        'constants.coolify.upgrade_script_url' => 'https://cdn.example.com/upgrade.sh',
+        'constants.ssh.mux_enabled' => false,
+    ]);
+
+    updateCoolifyTestCreateRootServerAndSettings([
+        'is_auto_update_enabled' => true,
+        'new_version_available' => true,
+        'docker_registry_url' => 'docker.io',
+    ]);
+
+    Http::fake([
+        '*' => Http::response([
+            'coolify' => ['v4' => ['version' => '4.0.10']],
+        ], 200),
+    ]);
+}
+
 afterEach(function () {
     Mockery::close();
 });
@@ -363,3 +407,50 @@ it('starts an upgrade when the previous upgrade status is older than the lock ex
     expect(RemoteProcessCommand::read(Activity::query()->latest('id')->first()))
         ->toContain("bash /data/coolify/source/upgrade.sh '4.0.10'");
 });
+
+it('skips an automatic update and notifies the root team when the disk is almost full', function () {
+    updateCoolifyTestPrepareUpgrade();
+    Notification::fake();
+    Team::findOrFail(0)->discordNotificationSettings()->update(['discord_enabled' => true, 'server_disk_usage_discord_notifications' => true]);
+
+    updateCoolifyTestActionWithDiskSpace(3.2)->handle();
+
+    expect(Activity::query()->count())->toBe(0)
+        ->and((bool) InstanceSettings::findOrFail(0)->new_version_available)->toBeTrue();
+    Notification::assertSentTo(
+        Team::findOrFail(0),
+        UpgradeSkippedLowDiskSpace::class,
+        fn (UpgradeSkippedLowDiskSpace $notification) => $notification->version === '4.0.10'
+            && $notification->availableGb === 3.2
+            && str_contains((string) $notification->toMail()->render(), '3.2 GB free'),
+    );
+});
+
+it('fails a manual update when the disk is almost full', function () {
+    updateCoolifyTestPrepareUpgrade();
+    Notification::fake();
+
+    expect(fn () => updateCoolifyTestActionWithDiskSpace(3.2)->handle(manual_update: true))
+        ->toThrow(Exception::class, 'Not enough free disk space to upgrade: 3.2 GB free, 5 GB required.');
+
+    expect(Activity::query()->count())->toBe(0);
+    Notification::assertNothingSent();
+});
+
+it('upgrades when the free disk space cannot be measured', function () {
+    updateCoolifyTestPrepareUpgrade();
+
+    updateCoolifyTestActionWithDiskSpace(null)->handle();
+
+    expect(RemoteProcessCommand::read(Activity::query()->latest('id')->first()))
+        ->toEndWith("bash /data/coolify/source/upgrade.sh '4.0.10' '1.0.14' 'docker.io'");
+});
+
+it('upgrades and tells the upgrade script to skip its disk space check when the user overrides it', function () {
+    updateCoolifyTestPrepareUpgrade();
+
+    updateCoolifyTestActionWithDiskSpace(3.2)->handle(manual_update: true, skipDiskSpaceCheck: true);
+
+    expect(RemoteProcessCommand::read(Activity::query()->latest('id')->first()))
+        ->toEndWith("bash /data/coolify/source/upgrade.sh '4.0.10' '1.0.14' 'docker.io' 'false' 'true'");
+});