diff --git a/src/system.js b/src/system.js
index aedf2a20f..c088f240b 100644
--- a/src/system.js
+++ b/src/system.js
@@ -240,18 +240,16 @@ class FilesystemUsageTask extends AsyncTask {
             this.emitData({ speed: -1 });
         }
 
-        const dockerDf = await docker.df({ abortSignal });
-        let usage = 0;
+        let usage = 0, dockerDf;
 
         for (const content of contents) {
             percent += (90/contents.length+1);
             if (abortSignal.aborted) return;
 
             this.emitProgress(percent,`Checking du of ${content.id} ${content.path}`);
-            if (content.id === 'docker') {
-                content.usage = dockerDf.LayersSize;
-            } else if (content.id === 'docker-volumes') {
-                content.usage = dockerDf.Volumes.map((v) => v.UsageData.Size).reduce((a,b) => a + b, 0);
+            if (content.id === 'docker' || content.id === 'docker-volumes') {
+                if (!dockerDf) dockerDf = await docker.df({ abortSignal });
+                content.usage = content.id === 'docker' ? dockerDf.LayersSize : dockerDf.Volumes.map((v) => v.UsageData.Size).reduce((a,b) => a + b, 0);
             } else {
                 const [error, usage] = await safe(du(content.path, { abortSignal }));
                 if (error) debug(`du error ${content.path}: ${error.message}`); // can happen if app is installing etc
@@ -261,7 +259,7 @@ class FilesystemUsageTask extends AsyncTask {
             this.emitData({ content });
         }
 
-        if (mountpoint === '/') this.emitData({ type: 'standard', id: 'other', usage: used-usage });
+        if (mountpoint === '/') this.emitData({ type: 'standard', id: 'os', usage: used-usage });
     }
 }