Raspberry Pi 4 USB Boot Config Guide for SSD / Flash Drives

Raspberry Pi 4 with Samsung 950 Pro NVME SSD
Raspberry Pi 4 with Samsung 950 Pro NVME SSD

The Raspberry Pi 4 is finally here and has a lot of exciting changes. One very major downside is that it doesn’t support true USB booting yet out of the box (like the 3 series did). The Raspberry Pi foundation states that it is being worked on and will be added back with a future update. No timeline has been given yet for that to happen but they state it’s one of their top priorities.

Most of my projects heavily depend on having good performing storage so sitting and waiting was not an acceptable solution. In this guide I’ll show you a workaround to use USB devices as your rootfs device and use a Micro SD card as bootloader only which gives us full SSD performance after boot! To see exactly how much of a performance difference this makes (spoiler: it’s gigantic) check out the Raspberry Pi Storage Benchmarks.

I highly recommend doing this on a completely new install. If you try to upgrade your old ones and something goes wrong there’s a good chance you might lose data. We will be modifying the boot partition, resizing partitions, etc. so don’t use a drive with any data on it unless you are positive you have all of the steps down!

Compatible USB Adapters

The Raspberry Pi 4 is proving to be picky about what SATA, M.2, etc. adapters will work in the USB 3.0 port. The USB 3.0 ports are the ones in the middle that are blue inside. The black ones are USB 2.0 and won’t give you the faster speeds the new Pi offers.

It’s very likely that some of these will be fixed via software and firmware updates and the Raspberry Pi Foundation has several open known issues related to USB 3. Until that happens though I will maintain a list here of known working ones and known problematic ones. It’s still very early in the release of the Pi 4 so we still have a lot to learn about which adapters work / don’t work. If you have working and nonworking adapters leave a comment and I’ll add it in this list.

If the adapters worked before on older Pis then one thing you can try is putting them in the black USB 2.0 ports. Obviously this is stupid because we all want the Pi 4 performance gains but if you end up needing to buy a new adapter this will give you a workaround until a replacement arrives!

Find USB adapter chipset

There are certain chipsets used in adapters that are known to be working/not working.

pi@raspberrypi:~ $ lsusb
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 174c:55aa ASMedia Technology Inc. Name: ASM1051E SATA 6Gb/s bridge, ASM1053E SATA 6Gb/s bridge, ASM1153 SATA 3Gb/s bridge, ASM1153E SATA 6Gb/s bridge
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

This is a lsusb dump of all my connected USB devices. I have bolded the line with the USB bridge device. We can see that the chipset is ASM1153E

Known Good Chipsets

  • ASMedia ASM115X (StarTech 2.5″ SATA, UGREEN USB Enclosure, several others)

Known Working Adapters

Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesStarTech 2.5″ SATA to USB 3.0 Adapter2.5″ SATA to USB 3.0Verified working great by myself and others on Pi 4
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesOrico Transparent 2.5″ SATA to USB 3.0 Enclosure2.5″ SATA to USB 3.1Confirmed working by Ashjas in comments
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesELUTENG 2.5″ SATA to USB 3.0 Adapter2.5″ SATA to USB 3.0The ELUTENG is one of the known working 2.5″ SATA to USB 3.0 adapters for the Pi 4
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesCSL 2.5″ SATA to USB 3.0 Adapter2.5″ SATA to USB 3.0The CSL SL adapter is confirmed to be working by Krikitt in the comments. Available in Europe. Not available in US.
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesShinestar NVME to USB 3.0 AdapterM.2 NVME to USB 3.0This is the adapter I’m using in the picture at the top of the article. It is for NVME M.2 drives only (need different one for M.2 SATA).
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesQNINE M.2 SATA to USB 3.0 EnclosureM.2 SATA to USB 3.0I used this enclosure to benchmark M.2 SATA Lite-On and SanDisk drives — working great in 3.0 ports.
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesUGreen M.2 SATA to USB 3.1 EnclosureUGreen M.2 SATA to USB 3.1 EnclosureReported as working well in the comments by John H. Reinhardt with a ASM1051E chipset
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesTanbin mSATA to USB AdaptermSATA to USB 3.0I used this mSATA to USB adapter for my Crucial M550 benchmark — working in 3.0 ports.
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesGeneric mSATA to USB 3.0 Adapter (fe2008)mSATA to USB 3.1Confirmed working in comments by Nico
Raspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesRaspberry Pi 4 USB Boot Config Guide for SSD / Flash DrivesCanakit Raspberry Pi 4 Power Supply (USB-C)USB-C Power SupplyCanakit has been making very reliable power supplies for several Pi generations now

Known Problematic Adapters (VERY COMMON)

Fix (some) USB Adapter Problems Using Quirks

Some of the very common adapters on the naughty list above (such as the Sabrent) can be made to work by using USB quirks to disable UAS mode on the drive. This lowers performance, but it’s still much faster than a SD card and your adapter won’t go to waste.

To find out the quirks we need to find the device ID string for your adapter and then add an entry to cmdline.txt telling the kernel to apply them on boot.

Find Your Adapter

To apply the quirks we first need to get the adapter id. We will use the sudo lsusb command:

$ sudo lsusb
 Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 002 Device 002: ID 174c:55aa ASMedia Technology Inc. Name: ASM1051E SATA 6Gb/s bridge, ASM1053E SATA 6Gb/s bridge, ASM1153 SATA 3Gb/s bridge, ASM1153E SATA 6Gb/s bridge
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

On line 2 we can see my ASM1051E SATA 6Gb/s bridge adapter (it’s the known working StarTech.com 2.5″ SATA to USB adapter). You will see something very similar to mine when you run the command and it shouldn’t be too hard to figure out which device it is. If you need more information add a -v switch to make the command sudo lsusb -v. This can sometimes add some additional details to make it easier to figure out which one is your adapter.

If you’re still not sure, we have another command that between the two that can narrow things down. Type / paste the following:

sudo dmesg | grep usb

 [    0.828535] usb usb3: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 4.19
 [    0.828568] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1
 [    0.828597] usb usb3: Product: DWC OTG Controller
 [    0.828620] usb usb3: Manufacturer: Linux 4.19.75-v7l+ dwc_otg_hcd
 [    0.828644] usb usb3: SerialNumber: fe980000.usb
 [    0.830051] usbcore: registered new interface driver uas
 [    0.830182] usbcore: registered new interface driver usb-storage
 [    0.836488] usbcore: registered new interface driver usbhid
 [    0.836511] usbhid: USB HID core driver
 [    0.971598] usb 1-1: new high-speed USB device number 2 using xhci_hcd
 [    1.154217] usb 1-1: New USB device found, idVendor=2109, idProduct=3431, bcdDevice= 4.20
 [    1.154254] usb 1-1: New USB device strings: Mfr=0, Product=1, SerialNumber=0
 [    1.154281] usb 1-1: Product: USB2.0 Hub
 [    1.301989] usb 2-1: new SuperSpeed Gen 1 USB device number 2 using xhci_hcd
 [    1.332965] usb 2-1: New USB device found, idVendor=174c, idProduct=55aa, bcdDevice= 1.00
 [    1.332999] usb 2-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1
 [    1.333026] usb 2-1: Product: ASM105x
 [    1.333048] usb 2-1: Manufacturer: ASMT
 [    1.333071] usb 2-1: SerialNumber: 123456789B79F

This is the dmesg log showing the hardware detection as hardware is activated on the Pi. If your log is really long you can generate fresh entries by just unplugging a device and plugging it back in and running the command again. Here we can clearly see that the ASM105x is what our StarTech adapter is being detected as.

Now we can go back to our first lsusb command and we want the 8 characters from the ID field that comes right after the Device:

Bus 002 Device 002: ID 174c:55aa ASMedia Technology Inc. Name: ASM1051E SATA 6Gb/s bridge

Our adapter’s ID is: 174c:55aa

Applying Quirks

To apply the quirks to our USB adapter we are going to edit /boot/cmdline.txt. Type:

sudo nano /boot/cmdline.txt

We are going to add the following entry into the very front of cmdline.txt:

usb-storage.quirks=XXXX:XXXX:u

In place of the X’s above you will put in your adapter’s ID that we got before. With the example commands I gave above mine would look like this: usb-storage.quirks=174c:55aa:u. After this my cmdline.txt looks like this (everything should be one continuous line, no line breaks!):

usb-storage.quirks=174c:55aa:u console=serial0,115200 console=tty1 root=PARTUUID=d34db33f-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait

Now reboot the Pi. If the Pi fails to boot you can plug the SD card into the computer and go to /boot/cmdline.txt and undo the change we did so you can boot back in with your SD card.

Verifying Quirks

Once you have rebooted after changing cmdline.txt we can verify the quirks have been applied by doing another dmesg | grep usb command:

sudo dmesg | grep usb
 [    1.332924] usb 2-1: New USB device found, idVendor=174c, idProduct=55aa, bcdDevice= 1.00
 [    1.332957] usb 2-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1
 [    1.332983] usb 2-1: Product: ASM105x
 [    1.333006] usb 2-1: Manufacturer: ASMT
 [    1.333028] usb 2-1: SerialNumber: 123456789B79F
 [    1.335967] usb 2-1: UAS is blacklisted for this device, using usb-storage instead
 [    1.336071] usb 2-1: UAS is blacklisted for this device, using usb-storage instead
 [    1.336103] usb-storage 2-1:1.0: USB Mass Storage device detected
 [    1.336479] usb-storage 2-1:1.0: Quirks match for vid 174c pid 55aa: c00000
 [    1.336611] scsi host0: usb-storage 2-1:1.0

This time we can see in dmesg that UAS was blacklisted for the device and it has loaded with the usb-storage driver instead. This driver tends to be more compatible with the “problematic adapters” but the performance is usually significantly lower. It’s definitely worth a try though as some adapters do better with the quirks performance-wise. The only way to know for sure is to run a benchmark (see storage benchmark section near the end).

USB Boot Instructions

There are a lot of steps to follow to set everything up properly. If you make a mistake the first time don’t spend too much time trying to correct it or figure out what you did wrong. It’s usually faster to burn the images again and reconfigure again rather than try to figure out which step you might have made a typo on. It’s much easier the second time!

Prepare SD Card

Download the latest Raspbian release from https://www.raspberrypi.org/downloads/raspbian/. Both Lite or Desktop versions will work. Win32DiskImager (Windows) or balenaEtcher (Linux, Mac OS X, Windows) are highly recommended to burn the images.

Note: Don’t attempt to use raw dd commands to write the images. Too many silly things can go wrong that are checked for/fixed by the recommended programs. Do yourself a big favor and use one of the recommends to avoid spending a ton of time troubleshooting basic imaging problems!

Preparing SSD

We are going to burn a second identical copy of Raspbian to the SSD. This ensures everything the Pi needs to boot is there so we can use the SD card as a bootloader but our actual system will be on our nice fast SSD drive.

Note: Make sure you create the empty file named “ssh” on the boot partition of both drives if you are headless or don’t have a mouse/keyboard attached so you can ssh in on the first boot.

First Boot (SD card only, SSD unplugged)

Insert your freshly imaged SD card into the Pi and connect the power. Sign into the Pi for the first time.

Don’t do an apt-get upgrade/dist-upgrade or any additional configuration yet. Just stick with the instructions until we have finished configuration (especially since if something goes wrong you may have to start over and any other setup you did will be lost).

Once the Pi has finished booting and you have signed in for the first time plug in your SSD to your Pi’s USB 3.0 ports. The USB 3.0 ports are the ones that have the blue plastic inside instead of the black plastic (the black ones are USB 2.0 ports).

Change PARTUUID

We need to change the PARTUUID of our SSD’s partitions so the Pi doesn’t get confused about what device to boot from. Right now the partitions on both the SD card and the SSD are an exact match and we need them to be different so we can tell the Pi to boot specifically from our SSD’s partition.

We are going to use fdisk to change the SSD’s PARTUUID to the hexadecimal d34db33f to make our SSD easy to identify. Use the following:

$ sudo fdisk /dev/sda

 Welcome to fdisk (util-linux 2.33.1).
 Changes will remain in memory only, until you decide to write them.
 Be careful before using the write command.
 Command (m for help): p
 Disk /dev/sda: 238.5 GiB, 256060514304 bytes, 500118192 sectors
 Disk model: ASM105x
 Units: sectors of 1 * 512 = 512 bytes
 Sector size (logical/physical): 512 bytes / 512 bytes
 I/O size (minimum/optimal): 512 bytes / 512 bytes
 Disklabel type: dos
 Disk identifier: 0x6c586e13
 Device     Boot  Start       End   Sectors   Size Id Type
 /dev/sda1         8192    532479    524288   256M  c W95 FAT32 (LBA)
 /dev/sda2       532480 500118191 499585712 238.2G 83 Linux
 Command (m for help): x
 Expert command (m for help): i
 Enter the new disk identifier: 0xd34db33f
 Disk identifier changed from 0x6c586e13 to 0xd34db33f.
 Expert command (m for help): r
 Command (m for help): w
 The partition table has been altered.
 Syncing disks.

That’s it. Let’s verify our change using blkid:

$ sudo blkid

/dev/mmcblk0p1: LABEL_FATBOOT="boot" LABEL="boot" UUID="5203-DB74" TYPE="vfat" PARTUUID="6c586e13-01"
/dev/mmcblk0p2: LABEL="rootfs" UUID="2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e" TYPE="ext4" PARTUUID="6c586e13-02"
/dev/sda1: LABEL_FATBOOT="boot" LABEL="boot" UUID="5203-DB74" TYPE="vfat" PARTUUID="d34db33f-01"
/dev/sda2: LABEL="rootfs" UUID="2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e" TYPE="ext4" PARTUUID="d34db33f-02"

Your /dev/mmcblk0 and /dev/sda devices should now be different from each other. The SD card’s ID is 6c586e13 and the SSD’s PARTUUID is now

Update /boot/cmdline.txt

We are going to change cmdline.txt to point to the SSD for booting instead of the SD card. First make a backup of your existing cmdline.txt file with the following command:

sudo cp /boot/cmdline.txt /boot/cmdline.txt.bak

We’ve now created a backup you can restore if something goes wrong. If you need to restore your backup plug the SD card into a computer/device and replace cmdline.txt with cmdline.txt.bak that we made above. Now your Pi should boot normally again.

Open up /boot/cmdline.txt using nano or your favorite text editor:

sudo nano /boot/cmdline.txt

The existing file will look like this:

console=serial0,115200 console=tty1 root=PARTUUID=6c586e13-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet init=/usr/lib/raspi-config/init_resize.sh

We are going to change the root=PARTUUID section to point to our new d34db33f PARTUUID like the following:

console=serial0,115200 console=tty1 root=PARTUUID=d34db33f-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet init=/usr/lib/raspi-config/init_resize.sh

Make the change and double check the line is what it should be,then press Ctrl+X to save our changes.

Note: cmdline.txt should be one long solid line with no breaks — don’t add any line breaks or the system won’t boot and you’ll need to restore the backup we made earlier!

Test SSD

We are now ready to test booting from the SSD. Restart your Pi by issuing a

sudo reboot

The first boot with your SSD can be slow due to running fsck on the drive. If you have a really large SSD it can take surprisingly long to check all that space. Once the check completes it will mark the drive clean and skip the disk check from now on. It can take over a minute or two sometimes for really big drives so give it at least that much time before assuming it didn’t work.

After signing in we can verify that the SSD is being used like this:

$ findmnt -n -o SOURCE /

 /dev/sda2

Verify that partition has switched over as shown below to /dev/sda2 (SSD) instead of /dev/mmcblk0p2 (SD card).

Update /etc/fstab

We are now ready to edit the /etc/fstab file to point to our updated drive. To edit the file type:

sudo nano /etc/fstab

Your current file will look like this:

$ cat /etc/fstab
proc            /proc           proc    defaults          0       0
PARTUUID=6c586e13-01  /boot           vfat    defaults          0       2
PARTUUID=6c586e13-02  /               ext4    defaults,noatime  0       1
sudo nano /etc/fstab

Your current file will look similar to this (PARTUUID varies based on your Raspbian image version):

cat /etc/fstab
proc            /proc           proc    defaults          0       0
PARTUUID=6c586e13-01  /boot           vfat    defaults          0       2
PARTUUID=6c586e13-02  /               ext4    defaults,noatime  0       1

We want to change the root ( / ) partition (PARTUUID ending with -02) to load our SSD’s PARTUUID instead of the SD card. Replace the 2nd partition’s PARTUUID field on the last line in the file with the d34db33f label we applied earlier with fdisk. After making the change my /etc/fstab file looks like this:

proc            /proc           proc    defaults          0       0
PARTUUID=6c586e13-01  /boot           vfat    defaults          0       2
PARTUUID=d34db33f-02  /               ext4    defaults,noatime  0       1

Press Ctrl+X to tell nano to save our changes. Now type sudo reboot to restart the Pi.

Note: We want to leave the first partition (https://origin.jamesachambers.com/boot) on the SD card. If you change this to the SSD then apt will update your SSD instead of the SD card so they won’t be used during boot! Remember that we are using the SD card as a bootloader and that is why the firmware updates (such as start.elf, etc) should go there instead of the SSD’s boot partition (which is never used).

Resizing Filesystem

By default the partition on the SSD / Flash drive will only be 1.8G. The Pi expands this automatically on micro SD drives but we will need to do it ourselves for a SSD / Flash drive. To do this we need to expand the partition and then resize the file system.

First let’s open fdisk and print the partitions:

pi@raspberrypi:~ $ sudo fdisk /dev/sda
 Welcome to fdisk (util-linux 2.33.1).
 Changes will remain in memory only, until you decide to write them.
 Be careful before using the write command.
 Command (m for help): p
 Disk /dev/sda: 238.5 GiB, 256060514304 bytes, 500118192 sectors
 Disk model: ASM105x
 Units: sectors of 1 * 512 = 512 bytes
 Sector size (logical/physical): 512 bytes / 512 bytes
 I/O size (minimum/optimal): 512 bytes / 512 bytes
 Disklabel type: dos
 Disk identifier: 0xd34db33f
 Device     Boot  Start     End Sectors  Size Id Type
 /dev/sda1         8192  532479  524288  256M  c W95 FAT32 (LBA)
 /dev/sda2       532480 4390911 3858432  1.9G 83 Linux

There is the line we need. Our start value for /dev/sda2 (rootfs) is 532480. Next we need to remove and recreate the partition as a larger size.

If you make any mistakes during this command just close fdisk by pressing q. The changes won’t be written to disk. If you mess up any of the commands the drive will no longer boot and you’ll have to start over again so be careful!

Command (m for help): d
 Partition number (1,2, default 2): 2
 Partition 2 has been deleted.
 Command (m for help): n
 Partition type
    p   primary (1 primary, 0 extended, 3 free)
    e   extended (container for logical partitions)
 Select (default p): p
 Partition number (2-4, default 2): 2
 First sector (2048-500118191, default 2048): 532480
 Last sector, +/-sectors or +/-size{K,M,G,T,P} (532480-500118191, default 500118191): 500118191 
 Created a new partition 2 of type 'Linux' and of size 238.2 GiB.
 Partition #2 contains a ext4 signature.
 Do you want to remove the signature? [Y]es/[N]o: N
 Command (m for help): w
 The partition table has been altered.
 Syncing disks.

If everything went well then type “w” and press enter. Otherwise press “q” to quit and try again. Once you enter “w” the changes will be permanently written to disk!

Now reboot the system. Type “df -h” to view the current disk:

pi@raspberrypi:~ $ df -h
 Filesystem      Size  Used Avail Use% Mounted on
 /dev/root       1.8G  1.3G  415M  76% /
 devtmpfs        1.8G     0  1.8G   0% /dev
 tmpfs           2.0G     0  2.0G   0% /dev/shm
 tmpfs           2.0G  8.5M  1.9G   1% /run
 tmpfs           5.0M  4.0K  5.0M   1% /run/lock
 tmpfs           2.0G     0  2.0G   0% /sys/fs/cgroup
 /dev/mmcblk0p1  253M   52M  201M  21% /boot
 tmpfs           391M     0  391M   0% /run/user/1000

We can see our disk is still 1.8G even after resizing the partition. That’s because we still have one more step! We need to resize the filesystem to fill our new partition space. For this we will use “sudo resize2fs /dev/sda2”:

sudo resize2fs /dev/sda2
 resize2fs 1.44.5 (15-Dec-2018)
 Filesystem at /dev/sda2 is mounted on /; on-line resizing required
 old_desc_blocks = 1, new_desc_blocks = 15
 The filesystem on /dev/sda2 is now 62448214 (4k) blocks long.

Now let’s check df -h again:

pi@raspberrypi:~ $ df -h
 Filesystem      Size  Used Avail Use% Mounted on
 /dev/root       235G  1.3G  224G   1% /
 devtmpfs        1.8G     0  1.8G   0% /dev
 tmpfs           2.0G     0  2.0G   0% /dev/shm
 tmpfs           2.0G  8.5M  1.9G   1% /run
 tmpfs           5.0M  4.0K  5.0M   1% /run/lock
 tmpfs           2.0G     0  2.0G   0% /sys/fs/cgroup
 /dev/mmcblk0p1  253M   52M  201M  21% /boot
 tmpfs           391M     0  391M   0% /run/user/1000

And that’s it! You will now be using all of your space on your drive.

Update Pi using apt

Now that we’ve updated fstab it is safe (and highly recommended) to update your Pi’s software. Type “sudo apt-get update && sudo apt-get dist-upgrade” to update the system and firmware.

Your system will now be running completely from your USB drive! To verify this, run the command “findmnt -n -o SOURCE” / to ensure your root partition has switched over as shown below to /dev/sda2 instead of /dev/mmcblk0p2.

Verify SSD Performance

You can make sure everything is running correctly (and as fast as it should be) by running my quick storage benchmark. You can run the benchmark with the following one-liner:

sudo curl https://raw.githubusercontent.com/TheRemote/PiBenchmarks/master/Storage.sh | sudo bash

This will give you a score you can compare to the other Raspberry Pi Storage Benchmark results and make sure that you are getting an equivalent speed to your peers with the same device!

Conclusion

The Samsung 950 Pro NVME drive in the featured picture scored a 9189 on the Raspberry Pi Storage Benchmark. The previous all-time record score on a Pi 3B+ was 3561. The performance gains are very real and very dramatic.

For me getting this performance is well worth having to waste a micro SD card just to be a bootloader. I am largely after the USB 3.0 bus and gigabit ethernet performance improvements and using this method I am able to achieve the performance I was after without waiting an indeterminate amount of time for the feature to be added back in!

Although there are ongoing compatibility issues and we lack the super easy native USB booting support we had before I’m more than willing to go through the growing pains to finally get rid that ancient USB 2.0 bus! Just make sure if you are planning to build a system you plan your adapters and parts accordingly.

331 thoughts on “Raspberry Pi 4 USB Boot Config Guide for SSD / Flash Drives”

  1. Avatar for Phil Bolduc

    I installed and tried Win32DiskImager, however, when flashing the .img I only got a single partition. It is really strange because when I had tried your instructions previously using an Orico adapter, I had different PARTUUIDs, but could not get it to work. So I ordered the ELUTEN ones. Now I am only getting MBR partitions. I spent an hour trying this morning at couldn’t get it working. I hope to find more time this next week to try again. I will continue following this page for any updates.

  2. Avatar for Phil Bolduc

    Does anyone else have the problem that the external drive has the same PARTUUID as the SD card? I tried using sgdisk, etc. I dont understand why my external SSD has the same PARTUUID as the SD card. Any suggestions?

    pi@raspberrypi:~ $ lsusb
    Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    Bus 002 Device 002: ID 174c:55aa ASMedia Technology Inc. Name: ASM1051E SATA 6Gb/s bridge, ASM1053E SATA 6Gb/s bridge, ASM1153 SATA 3Gb/s bridge, ASM1153E SATA 6Gb/s bridge
    Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
    Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

    pi@raspberrypi:~ $ sudo blkid
    /dev/mmcblk0p1: LABEL_FATBOOT=”boot” LABEL=”boot” UUID=”5203-DB74″ TYPE=”vfat” PARTUUID=”6c586e13-01″
    /dev/mmcblk0p2: LABEL=”rootfs” UUID=”2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e” TYPE=”ext4″ PARTUUID=”6c586e13-02″
    /dev/sda1: LABEL_FATBOOT=”boot” LABEL=”boot” UUID=”5203-DB74″ TYPE=”vfat” PARTUUID=”6c586e13-01″
    /dev/sda2: LABEL=”rootfs” UUID=”2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e” TYPE=”ext4″ PARTUUID=”6c586e13-02″
    /dev/mmcblk0: PTUUID=”6c586e13″ PTTYPE=”dos”

    1. Avatar for jamesachambers

      If you are using MBR instead of GPT then you need to use fdisk’s advanced menu to change the PARTUUID. Using MBR is also why the PARTUUIDs are the same. If you google “PARTUUID same” you’ll see all Raspberry Pi posts going back for years as this has been a problem ever since Raspbian started using PARTUUIDs instead of the old /dev/mmcblk2p1 way.

      Give fdisk’s expert menu a go instead of gdisk and I think you’ll be all set!

      I’m going to add this to the instructions (it looks like from the comments there’s a couple other things I need to edit in there as well that come up a lot).

      1. Avatar for Marius

        I have the same problem and cant get it to work. Same partuuid. Would be nice if you add it to the instructions. Thank you!

    2. Avatar for Phil Bolduc

      This is really odd. Maybe it is the flasher I am using. I changed my external SSD to GPT using Windows and confirmed in the PI,

      pi@raspberrypi:~ $ sudo blkid
      /dev/mmcblk0p1: LABEL_FATBOOT=”boot” LABEL=”boot” UUID=”5203-DB74″ TYPE=”vfat” PARTUUID=”6c586e13-01″
      /dev/mmcblk0p2: LABEL=”rootfs” UUID=”2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e” TYPE=”ext4″ PARTUUID=”6c586e13-02″
      /dev/mmcblk0: PTUUID=”6c586e13″ PTTYPE=”dos”
      /dev/sda1: PARTLABEL=”Microsoft reserved partition” PARTUUID=”f0045a2f-9945-47d6-a37c-3afa339052cb”

      Then I used balena-etcher (1.5.57) to flash 2019-09-26-raspbian-buster-lite.zip to the SSD. When mounting it back in the Raspberry Pi, it was back to MBR,

      pi@raspberrypi:~ $ sudo blkid
      /dev/mmcblk0p1: LABEL_FATBOOT=”boot” LABEL=”boot” UUID=”5203-DB74″ TYPE=”vfat” PARTUUID=”6c586e13-01″
      /dev/mmcblk0p2: LABEL=”rootfs” UUID=”2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e” TYPE=”ext4″ PARTUUID=”6c586e13-02″
      /dev/mmcblk0: PTUUID=”6c586e13″ PTTYPE=”dos”
      /dev/sda1: LABEL_FATBOOT=”boot” LABEL=”boot” UUID=”5203-DB74″ TYPE=”vfat” PARTUUID=”6c586e13-01″
      /dev/sda2: LABEL=”rootfs” UUID=”2ab3f8e1-7dc6-43f5-b0db-dd5759d51d4e” TYPE=”ext4″ PARTUUID=”6c586e13-02″

      Perhaps there is a different flashing utility I should be using? It seems balena-etcher always writes as MBR? I am flashing my SD and SSD on a Windows machine.

  3. Avatar for ciB

    I flashed bot SSD and SD card with etcher, but now both my devices have the same partuuuid. I tried changing it with gdisk, but my drives are using mbr and not gbt. How should I proceed? could I use the UUID instead?

  4. Avatar for Mario

    I just tested “Sabrent 2.5-Inch SATA to USB 3.0 Tool-Free External Hard Drive Enclosure” and it boots perfectly from USB 3.0 port.
    https://www.amazon.com/gp/product/B00OJ3UJ2S

    I fixed the problem of keyboard and mouse not working in Buster (Desktop version). It turns out I updated the system on micro SD card too early. I just had to overwrite boot contents on micro SD with the ones from SSD that was just freshly flashed. Hope this helps some folks.

  5. Avatar for Markus

    Thank you for that very good explanation. But one question remains. Do I still need the SD card in the Raspberry Pi slot?

    1. Avatar for jamesachambers

      Hey Markus,

      This is still necessary as a workaround for now until the Pi 4 official USB booting support is released

  6. Avatar for Mario

    Buster desktop booted fine off SSD but keyboard and mouse is not working. I am running the latest firmware version. Please help.

    1. Avatar for jamesachambers

      Hey Mario,

      This happens if apt-get upgrade is ran before the final step. The reason is if you update before everything else is in place things like kernel8.img won’t be the same on both the SD card and the USB drive which will cause the kernel modules to fail to load (breaking your USB).

      Wait until the very final step before upgrading anything. Ignore any prompts that you get saying there’s updates available, etc. until after the very final step and you won’t encounter this!

  7. Avatar for dave

    hi I have the startech usb adapter and a 128gb ssd attached following the instructions it reboots after changing the config.txt to boot to the new drive.
    upon rebooting I can see the First line of text that flashes through failed to load kernel modules! it continues to boot to the ssd but I get no mouse or keyboard working and cannot connect via ssh even though the screen says its loaded but the password needs changing from default
    have I done something wrong?

    many thanks

    1. Avatar for jamesachambers

      Hey dave,

      This means that apt-get upgrade was ran before the final step so your SD card and your SSD no longer match. Don’t update until after the very final step and you will be fine!

  8. Avatar for Mikel Finch

    Great article. My only change is that I setup my USB HDD by hand and copy data via rsync.

    So, my setup that follows assumed you have a big USB HDD with one huge partition (/dev/sda1). Imaging my HDD is a bad idea since I need a GUID partition table. I setup ssh to edit fstab and cmdline.txt

    Steps are…

    – image microsd
    – boot from microsd
    – setup ssh / hostname and reboot (sudo raspi-config)
    – connect and prepair USB HDD (fdisk, mkfs -t ext4)

    sudo mount /dev/sda1 /media/new

    – copy microsd to USB HDD

    sudo rsync -avx –exclude=’/media/’ / /media/new

    – setup for USB boot (boot/cmdline.txt and /etc/fstab)

    sudo blkid

    /dev/sda1: UUID=”e4cd2f42-6785-42e5-9de1-56282d3ffd0a” TYPE=”ext4″ PARTUUID=”36af4b27-4fc2-af4f-9ae2-804b8226f594″

    cd /boot
    sudo cp cmdline.txt cmdline.txt.back
    sudo vi cmdline.txt

    dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=PARTUUID=36af4b27-4fc2-af4f-9ae2-804b8226f594 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait

    cd etc
    sudo cp fstab fstab.bak
    sudo vi fstab

    PARTUUID=36af4b27-4fc2-af4f-9ae2-804b8226f594 / ext4 defaults,noatime 0 1

    sudo reboot

    – verify setup

    findmnt -n -o SOURCE /
    /dev/sda2

    1. Avatar for jamesachambers

      Hey Mikel,

      Thanks for sharing your steps! I had not done it this way before but I’m sure this will help a lot of people who also need/want to maintain their existing partition table.

    2. Avatar for Craig

      Hi Mikel, that’s an awesome addition to this guide. Had to read your commands and the detailed guide by James together to work it out but I’ve migrated my Pi4 without having to reinstall the OS and Hassbian/Home Assistant. Performance improvement is massive due to the SSD.

      1. Avatar for jamesachambers

        I agree! It’s so awesome that it’s going to go in the guide as this step has been burning a lot of people and this works even if apt-get upgrade runs and essentially lets you fix it without starting over.

  9. Avatar for Didier B

    Thanks for sharing this tutorial.
    Note : In step 2, I used the Raspbian’s accessory : ‘SD CARD Copier’ to ‘image’ the USB SSD. This has the additional benefit to avoid the need for Sep 9 as the file system is automatically extended !

  10. Avatar for FunWithPis

    Hmm I tried this and it boots and I can SSH in to it but the keyboard and mouse directly hooked up to the pi4 stops working the second I boot from the USB drive.. Any Idea’s on how to fix this?
    It works perfectly fine until I reboot to the USB (kingwin adapter, ASMedia Technology Inc. Name: ASM1051E SATA M.2)

    The keyboard is a generic dell branded Keyboard (Model: L20U) and the mouse is a Logitech (unified receiver but the mouse is a M705)

    1. Avatar for FUNWITHPIS

      Never mind if I read the comments closer I would of noticed that you don’t update until the very very end after resizing. It works perfectly!

  11. Avatar for marvin

    Hmmm, I never thought of dd-ing raspbian to SD card and Ubuntu to USD disk, I always used just SD and then did a cp afterwards. This is a very interesting idea, thank you

  12. Avatar for Antonio

    Same here, no mouse or keyboard when following the exact steps.
    Problem seems to be the update bit.
    Do not update until the very end (last step).
    Working fine now.

    1. Avatar for jamesachambers

      Hey Antonio,

      Thanks for the feedback. I have updated the guide and moved updating to the very last step (now step #10).

  13. Avatar for Achi

    The installation was OK, everything works fine, but I lost the wlan0 interface and the message ‘rfkill: cannot open /dev/rfkill: No such file or directory’ appears after ssh login

    1. Avatar for jamesachambers

      Hey jim,

      Thanks, I have made this a lot more prominent in both the step by step instructions and the updating fstab section.

  14. Avatar for Zerschranzer

    If you got trouble to boot from your ssd/hdd via usb 3.0, try to flash the new raspbian x86_64 kernel. First put your ssd/hdd on an usb 2.0 port, to be able to boot. Than run :
    “sudo rpi-update” , wait for it to finish.
    Than edit your /boot/config.txt and add “arm_64bit=1” to the bottom of it. (Without the “”). Shutdown your pi, put your ssd/hdd in to an usb 3.0 port and start it. You should now be able to use it. It solved my problem with ultra bad I/O performance (more than 10 minutes to boot) with an intenso portable ssd.

  15. Avatar for Zerschranzer

    i dont got a second ssd for my raspi, but a good usb 3.0 hdd. Do you think the perfomance with an hdd will be better, compared to a midrange sdhc ?
    i just want to run a minecraft server.

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