How to Fix a Second Hard Drive Not Showing Up in Ubuntu
In the Ubuntu of system administration, a "missing" second hard drive is a common hurdle, especially after a fresh install or when adding new hardware. In 2026, while Ubuntu 24.04 and 26.04 are better than ever at hardware detection, specific settings like Intel VMD, RAID modes, or uninitialized partitions can still keep your storage hidden from the file manager. This guide will walk you through the three stages of "finding" your drive.
Stage 1: Hardware & BIOS Check (The "Invisible" Drive)
If your drive doesn't appear in the "Disks" utility at all, the issue is likely at the hardware or firmware level. Linux often struggles to see drives if the BIOS/UEFI is set to a proprietary mode like Intel RST (RAID) or VMD.
- SATA Operation: Enter your BIOS (usually F2 or Del) and ensure your SATA/Storage mode is set to AHCI instead of RAID On.
- Disable VMD: On newer Intel-based laptops (like ASUS or Dell), look for VMD Controller in the BIOS and set it to Disabled.
- Physical Connection: Ensure cables are seated firmly. On NVMe drives, reseating the stick in the M.2 slot often fixes intermittent detection.
Stage 2: Initializing and Formatting (The "Unallocated" Drive)
If the drive is physically detected but doesn't show in the Sidebar, it might be uninitialized (no partition table) or formatted in a way Ubuntu doesn't automatically mount.
- Open the Disks utility (search "Disks" in the Activities menu).
- Select the secondary drive from the left panel.
- If you see "Free Space," click the + (plus) icon to create a new partition.
- Format Choice: Use Ext4 if you only use Linux. Use NTFS if you dual-boot with Windows and need shared access.
- Mounting: Click the "Play" (triangle) icon to mount it manually.
Stage 3: Permanent Mounting (Automount at Startup)
By default, Ubuntu often treats secondary drives as "removable," meaning they won't mount until you click them. For 2026 workflows like hosting a media server or database, you need the drive to mount automatically on boot via /etc/fstab.
The Graphical Way (Recommended for Beginners)
- In Disks, select your partition and click the Gear icon.
- Select Edit Mount Options...
- Toggle User Session Defaults to OFF.
- Check Mount at system startup and Show in user interface.
- Click OK and enter your password.
The Terminal Way (For Servers/Advanced Users)
To manually edit your mount table for maximum stability:
- Get your drive's unique ID:
sudo blkid - Create a mount point:
sudo mkdir /mnt/data - Edit fstab:
sudo nano /etc/fstab - Add this line to the end:
UUID=YOUR-UUID-HERE /mnt/data ext4 defaults,nofail 0 2
| Option | Function | Why use it? |
|---|---|---|
| defaults | Standard permissions. | General usage. |
| nofail | Ignore if drive missing. | Prevents boot hang if drive is unplugged. |
| 0 2 | Dump/Pass flags. | Tells Ubuntu to check disk for errors at boot. |
Stage 4: Fixing Permissions (The "Read Only" Error)
Sometimes you can "see" the drive, but you can't create folders. This happens because the root user owns the mount point. To fix this, run:
sudo chown -R $USER:$USER /path/to/your/mount
Conclusion
In 2026, the Ubuntu Categories support community has identified AHCI mode and fstab configuration as the two most critical steps for storage management. If you still can't see the second hard drive, check sudo dmesg | grep -i sata to see if the kernel is throwing errors during the boot-up probe. By setting up a permanent mount point with nofail, you ensure your second hard drive is always ready for your projects and data storage needs.
Keywords
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