Step-by-step guide

How to locate and replace a bad hard drive in a QNAP NAS or server

By Gabriel · 2026-11-12

What you will do: identify exactly which bad hard drive in a QNAP NAS or server is failing, make its LED blink with the Locate action, and swap it for a new drive without pulling the wrong one.

In a NAS or a data center with many drives it is easy to replace the wrong disk. This guide uses a QNAP 1635 with a disk that reported a SMART error. Other brands work in a similar way, though the menus may look a little different.

DifficultyEasy

TimeAbout 15 minutes (plus RAID rebuild, up to about 24 hours)

Tools & requirementsQNAP NAS or server with multiple hard drives (QNAP 1635 shown), Replacement hard drive of the same model as the failing one, Access to the QNAP web interface (QTS), locally or remotely, Marker to write the purchase date on the new drive (optional)

Step 1: Read the bad disk error in Event Notifications

QNAP Event Notifications panel showing a Disk S.M.A.R.T. warning: Disk 5 complete test result fatal or unknown error, the sign of a failing hard drive in the NAS

Open the notification to see the full error. Here it says the Disk 5 SMART test result is a fatal or unknown error.
That disk is going bad. Replace it before it dies completely so you don't lose data.

Caution: On a home desktop you might mark bad sectors and keep using a drive. When the data matters, don't risk it. Replace the drive.

Step 2: Open Storage & Snapshots

QNAP QTS desktop with the Storage and Snapshots app icon, used to find which hard drive in the NAS has failed

In the QNAP interface, use the menu on the left (or the desktop icon).
Click Storage & Snapshots.

Step 3: Find the bad drive in the disk list

QNAP Storage and Snapshots disk list for the NAS host with Disk 5 marked in red as the bad hard drive among disks 1 to 12

The side panel lists every drive. The bad one stands out, here Disk 5.
You could count the bays on the device (1, 2, 3, 4, 5) and pull that one. But with many units, or with a technician doing the swap, counting is how mistakes happen.

Step 4: Check the disk information

QNAP Disk Information panel showing an Abnormal status for a Seagate ST10000NM0016 9.10 TB hard drive with model number, capacity and temperature

Select the disk to see its details: model, model number, capacity, status and temperature.
The status shows Abnormal. Note the model so you can buy the same one.

Step 5: Use Action > Locate to make the drive blink

Click Action, then Locate.
A pop-up says the disk LEDs are blinking. The light on that drive's tray blinks on the NAS.
This works remotely too, so someone on site can see exactly which drive to pull.

Step 6: Pull out the blinking drive tray

Hand pulling the blinking hard drive tray out of a QNAP NAS to remove the failing drive

Push the tray release on the blinking bay.
Slide the tray with the old drive out of the NAS.

Step 7: Handle the drive by its edges

Old hard drive removed from the NAS tray showing its circuit board, which should not be touched because static can damage the drive

Hold drives by the sides, not by the circuit board.

Caution: Avoid touching the electronics. Static can damage the drive.

Step 8: Release the drive from the plastic tray

QNAP plastic hard drive tray side rail being pulled out to release the drive pins from the holes on the side of the hard drive

On QNAP trays, pull the plastic rail on the side of the tray outward.
That releases the drive. Take the old drive out.

Step 9: Put the new drive in the tray

New Seagate Exos hard drive placed in a QNAP drive tray with the side holes lined up with the tray pins

Place the new drive the same way the old one was.
Line up the holes on one side, then snap the rail back on the other side.

Caution: Use the same model as the old drive. Check the model on the label against the old one.

Step 10: Write where and when you bought it

Writing the store name and purchase date on the label of a new hard drive with a marker to keep track of the warranty

Optional tip: write the store (for example Amazon or eBay) and the purchase date on the drive.
Then you'll know when you bought it if you ever need warranty.

Step 11: Push the tray back into the NAS

QNAP NAS front LCD showing Error Message HDD5 Ejected after the failing hard drive was removed

Slide the tray with the new drive back into the same bay.
The LCD message about HDD5 being ejected came from pulling the old drive. Once the new one is in, the system goes back to normal.

Step 12: Let the RAID rebuild

QNAP Storage and Snapshots disk table showing the new hard drive status as Rebuilding while the other drives show Good

Open the disk view again. The new drive shows Rebuilding while data is copied to it.
The rebuild can take several hours, around 24 hours here. You can keep using the NAS meanwhile.

Frequently asked questions

How do I find which hard drive is bad in a QNAP NAS?

Open Storage & Snapshots. The failing disk is marked in the disk list and shows an Abnormal status. Then use Action > Locate so the LED on that drive blinks.

Can I locate a bad NAS drive remotely?

Yes. The Locate action is clicked from the web interface, so you can make the drive blink remotely and have a technician on site pull the right one.

Should I keep using a hard drive with SMART errors in a NAS?

Not when the data is important. Replace it before it fails completely so you don't lose data.

How long does a QNAP RAID rebuild take after replacing a drive?

It can take several hours. In this example it was expected to take about 24 hours, and the NAS can still be used while it rebuilds.

Does this work on other NAS or server brands?

Most systems work in a similar way. The menu may be a little different, but you look for the failing disk and use a locate or identify option to blink its LED.

Need help with this?

Call, text or WhatsApp me at 859-878-0554.

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Watch the video

Original video: how to locate a bad HDD in a NAS or server QNAP?

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