diff --git a/src/system.js b/src/system.js
index 62a7346e3..9cbc112f2 100644
--- a/src/system.js
+++ b/src/system.js
@@ -91,14 +91,14 @@ async function getSwaps() {
 
 // this gets information based on mounted filesystems
 async function getFilesystems() {
+    const FS_TYPES = [ 'ext4', 'xfs', 'cifs', 'nfs', 'fuse.sshfs' ]; // we don't show size of contents in untracked disk types
+
     const [dfError, dfEntries] = await safe(df.filesystems());
     if (dfError) throw new BoxError(BoxError.FS_ERROR, `Error running df: ${dfError.message}`);
 
     const filesystems = {}; // by file system
     let rootDisk;
 
-    const FS_TYPES = [ 'ext4', 'xfs', 'cifs', 'nfs', 'fuse.sshfs' ]; // we don't show size of contents in untracked disk types
-
     for (const dfEntry of dfEntries) {
         if (!FS_TYPES.includes(dfEntry.type)) continue;
         if (dfEntry.mountpoint === '/') rootDisk = dfEntry;
@@ -233,25 +233,25 @@ async function updateDiskUsage(progressCallback) {
 
     let percent = 1;
 
+    const dockerDf = await docker.df();
+
+    const fsCount = Object.keys(filesystems).length;
     for (const fsPath in filesystems) {
         const filesystem = filesystems[fsPath];
 
-        if (filesystem.type === 'ext4' || filesystem.type === 'xfs') {
-            const [speedError, speed] = await safe(hdparm(filesystem));
+        if (filesystem.type === 'ext4' || filesystem.type === 'xfs') { // hdparm only works with block devices
+            const [speedError, speed] = await safe(hdparm(fsPath));
             if (speedError) progressCallback({ message: `hdparm error: ${speedError.message}`});
             filesystem.speed = speedError ? -1 : speed;
         } else {
             filesystem.speed = -1;
         }
 
-        percent += (100/filesystems.length);
-        progressCallback({ percent, message: `Checking contents of ${filesystem}`});
-
-        const dockerDf = await docker.df();
-
+        percent += (100/fsCount);
+        progressCallback({ percent, message: `Checking contents of ${fsPath}`});
 
         for (const content of filesystem.contents) {
-            progressCallback({ message: `Checking du of ${JSON.stringify(content)}`});
+            progressCallback({ message: `Checking du of ${content.id} ${content.path}`});
             if (content.id === 'docker') {
                 content.usage = dockerDf.LayersSize;
             } else if (content.id === 'docker-volumes') {