General discussion • Re: Netboot (not PXE) experiences

@ronr I finally managed to get the RPis to use a nfs mounted root partition from my Synology. But I had to update some files and it took me a while until I detected the Synology (or nfs) behaves strange.

Even I have

Code:

pi@raspberrypi-trixie-dhcptest:/pxe-images/pxe-boot/87f728f5 $ cat cmdline.txt root=/dev/nfs nfsroot=192.168.0.9:/volume1/pxe_images/pxe-root,vers=3 rw ip=dhcp rootwait

and

Code:

root@synology:/volume1/pxe_images/pxe-root# cat 87f728f5/etc/fstab proc            /proc           proc    defaults          0       0192.168.0.194:/pxe-images/pxe-boot/87f728f5 /boot/firmware nfs defaults,vers=4.1,proto=tcp 0 0192.168.0.9:/volume1/pxe_images/pxe-root/87f728f5 /     nfs defaults,vers=4.1,proto=tcp 0 0

the client uses

Code:

pi@raspberrypi:~ $ mount | grep 192.168.0.9192.168.0.9:/volume1/pxe-root/87f728f5 on / type nfs (rw,relatime,vers=3,rsize=131072,wsize=131072,namlen=255,hard,nolock,proto=tcp,port=2049,timeo=600,retrans=3,sec=sys,local_lock=all,addr=192.168.0.9)

For some unknown reasons 192.168.0.9:/volume1/pxe_images/pxe-root/87f728f5 is not used and 192.168.0.9:/volume1/pxe-root/87f728f5 has to exist Looks like your approach to have both pxe-boot and pxe-root below pxe-images doesn't work on a Synology.

The file updates (primarily IP and nfs path updates) were obvious and quickly done. The fact that Synology ignores the exported root directory name and requires pxe-root to exist and doesn't use pxe-images/pxe-root took me two days to debug

I can't figure out what you're doing.

On a fresh installation of Raspberry Pi OS on the Raspberry Pi you wish to be the netboot server:

1. Create an empty /pxe-images/ directory and add an entry to fstab to mount the Synology on /pxe-images/ on every boot. Reboot and ensure the Synology is mounted on /pxe-images/ before running pxe-install. Verify that /pxe-images/ is an empty directory on the Synology.

2. Run pxe-install.

3. Run pxe-add.

That's all you should be doing. You shouldn't be installing anything else nor making other modifications.

If everything worked properly with a USB flash drive mounted on /pxe-images/, then there should be no difference with the Synology mounted on /pxe-images/. The scripts can't tell the difference.

Statistics: Posted by RonR — Tue Dec 30, 2025 12:01 am

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