Upgrading My Raspberry Pi 5 from microSD to NVMe SSD — Without Reinstalling the OS

How I migrated my existing Raspberry Pi OS to a 256GB NVMe SSD using the Pimoroni NVMe Base, and accidentally disrupted my home network along the way.

Why I decided to upgrade
I’ve been gradually expanding my homelab, and one of the devices I use is a Raspberry Pi 5 with 8GB RAM.

Initially, I was running Raspberry Pi OS Lite from a 128GB microSD card.

It worked fine, but I wanted something better suited for running containers, Kubernetes experiments, monitoring tools, and other self-hosted services.

So I decided to move my operating system to an NVMe SSD.

The goal was simple:

• Keep my existing Raspberry Pi OS installation.
• Preserve installed applications and configurations.
• Move everything from microSD to NVMe.
• Boot directly from the SSD.
• Avoid reinstalling and configuring everything again.

And, ideally, not break anything else in my homelab. 😅

Hardware used

Here’s the setup I used:

Raspberry Pi 5, 8 GB RAM
Original storage 128GB microSD
New storage: 256 GB NVMe SSD,
NVMe adapter: Pimoroni NVMe Base PIM699O
Raspberry Pi OS Lite (64-bit)

The Pimoroni NVMe Base connects to the Raspberry Pi 5’s PCIe interface using a ribbon cable.

One benefit of this setup is that I can keep using the existing OS and migrate it to faster storage.

Step 1: Install the NVMe SSD

First, shut down the Raspberry Pi.

sudo poweroff

Disconnect the power supply before installing the NVMe Base.
Install the SSD onto the Pimoroni board, connect the PCIe ribbon cable to the Raspberry Pi 5, and secure the adapter.
Make sure the ribbon cable is properly seated at both ends.
Keep the existing microSD card installed for now.
Power on the Pi normally.

Step 2: Verify that the NVMe SSD is detected

Connect to the Raspberry Pi using SSH or a keyboard and monitor.
Run:

lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINTS,MODEL

In my case, the output showed two storage devices:

mmcblk0     119.1G
nvme0n1     238.5G

mmcblk0 was the existing microSD card, while nvme0n1 was the new SSD.
I also checked the PCIe devices:

lspci -nn

My SSD appeared as a MAXIO Technology MAP1202 NVMe controller.That confirmed the adapter and SSD were being detected.

Step 3: Check the Raspberry Pi bootloader

The Raspberry Pi 5 needs a compatible bootloader to boot from NVMe storage.
Check the installed version:

sudo rpi-eeprom-update

I also checked the configured boot order:

sudo rpi-eeprom-config

If the firmware is outdated, update the system and bootloader before migrating.

sudo apt update
sudo apt full-upgrade -y

Pimoroni recommends Raspberry Pi 5 firmware dated December 6, 2023 or newer for the NVMe Base.
The bootloader version can also be managed through sudo raspi-config.

Step 4: Clone Raspberry Pi OS to the SSD

This was the main part of the migration.

Since I wanted to keep my existing OS, applications, SSH configuration, and other settings, I chose to clone the microSD installation rather than start from scratch.
Before cloning, verify the current root filesystem:

findmnt -no SOURCE /

While running from the microSD card, the expected result is:

/dev/mmcblk0p2

Important: Back up important data before proceeding. Stop any services that actively write to disk, such as databases, Docker containers, and K3s workloads.

A live block-level clone can capture inconsistent application data. For critical systems, use an offline cloning environment instead.

The cloning command is:

sudo dd if=/dev/mmcblk0 of=/dev/nvme0n1 \
  bs=4M status=progress conv=fsync

Here’s what it does:

• if specifies the source disk (microSD).
• of specifies the destination disk (NVMe).
• bs=4M sets the copy block size.
• status=progress shows copying progress.
• conv=fsync flushes written data before completion.

Warning: This overwrites the entire destination SSD. Confirm the device names carefully before running it.

After copying, the NVMe contains the OS installation and its boot and root partitions.

Step 5: Configure the Raspberry Pi to boot from NVMe

Next, I configured the boot order.

sudo raspi-config

Navigate to:

Advanced Options → Boot Order → NVMe/USB Boot

Finish and shut down:

sudo poweroff

I removed the original microSD card and powered the Pi back on.

This is an important verification step because it ensures the Raspberry Pi isn’t silently booting from the old microSD card.

It also avoids running with two cloned drives containing duplicate filesystem identifiers.

Step 6: Verify that the OS is running from NVMe

After rebooting, I checked the root filesystem:

findmnt -no SOURCE /

The output was:

/dev/nvme0n1p2

Success! The Raspberry Pi was now running its OS directly from NVMe storage.

I also checked the partitions:

lsblk -f

My output showed:

nvme0n1
├─nvme0n1p1  vfat  bootfs  /boot/firmware
└─nvme0n1p2  ext4  rootfs  /

The operating system and boot partition were both located on the NVMe SSD.

Step 7: Expand the filesystem

When cloning from a smaller card to a larger SSD, the filesystem might initially retain the original storage size.

You can check this with:

df -h /

If necessary, use the filesystem expansion option in raspi-config, or carefully grow the root partition and filesystem using appropriate Linux utilities.

In my case, the filesystem expansion was already successful.

My final result:

Filesystem       Size  Used  Avail  Use%
/dev/nvme0n1p2   235G  8.2G   217G    4%

I now had the full SSD capacity available without reinstalling the OS.

Step 8: Check NVMe health

After completing the migration, I installed NVMe monitoring tools:

sudo apt install -y nvme-cli smartmontools

Then I checked the SSD health:

sudo nvme smart-log /dev/nvme0n1

Some results from my SSD:

Press enter or click to view image in full size

The SSD looked healthy.

I also checked PCIe speed:

sudo lspci -vv | grep -E 'LnkCap:|LnkSta:'

The SSD was using PCIe Gen 2 ×1 at 5 GT/s, which is normal for Raspberry Pi 5.

PCIe Gen 3 is possible experimentally, but I decided to prioritise stability over maximum speed.

The unexpected problem: My internet stopped working!

The NVMe migration wasn’t the only lesson from this upgrade.
While working on my Raspberry Pi, I suddenly noticed network connectivity problems on my Mac.

At first, I thought something was wrong with my router or internet connection.
Then I remembered how I’d configured my homelab.

I use Tailscale for remote access, and my Raspberry Pi was advertising a subnet route to my home network.
I had disconnected that very Raspberry Pi during the storage upgrade.

My Mac was still connected to Tailscale, but a route it depended on was no longer available.
That explained why parts of my home network were unreachable.
If DNS also depends on resources behind a failed subnet route, even normal internet browsing can appear broken.
The lesson was simple: a device that looks unimportant during maintenance might actually be providing critical network connectivity.

Before taking down a homelab device, check whether it’s acting as a DNS server, subnet router, exit node, reverse proxy, or other shared service.
For a more resilient setup, I want to avoid relying on a single Raspberry Pi for important network routes.

Final results

The storage migration was successful.

• Raspberry Pi OS now boots from NVMe.
• Existing OS configurations were retained.
• Root filesystem uses the larger SSD.
• NVMe SMART health checks look good.
• The original microSD card is available as a recovery option.

And I learned a useful lesson about network dependencies along the way.

What I’d do differently next time

Before performing hardware maintenance, I’d check which services depend on the device.

I’d also make sure I had local network access that didn’t depend on Tailscale and a backup of any important application data.

For anyone running Raspberry Pi devices as part of a homelab, I recommend keeping a simple record of device roles and dependencies.

A storage upgrade is straightforward until the device you’re upgrading turns out to be part of your network infrastructure.

That’s the interesting part of building a homelab. Even small changes teach you something new.

Useful references

• Pimoroni: https://learn.pimoroni.com/article/getting-started-with-nvme-base
• Raspberry Pi documentation: https://www.raspberrypi.com/documentation/
• Tailscale documentation: https://tailscale.com/kb/