new pi5 with m.2 hat can not find ssd

USB SSD drive mounted for extra storage or NVME device attached to the PCIe connector you want to boot from?

hello

ist nur eine info

https://www.raspberrypi.com/documentation/computers/configuration.html

Example config.txt

Boot_Order options:
The BOOT_ORDER property defines the order for the different boot modes. It is read from right to left and up to 8 digits can be defined.
In the example set above “BOOT_ORDER=0xf416” this is 6-1-4-f:
6 = First boot attempt from NVME
1 = Second boot attempt from SD card
4 = Third boot attempt from USB
f = Loop – start again at the first boot attempt

############
BOOT_UART=1
POWER_OFF_ON_HALT=0
BOOT_ORDER=0xf146
PCIE_PROBE=1
dtparam=pciex1
dtparam=pciex1_gen=3
include distroconfig.txt

Run 
sudo raspi-config                  -->raspi-config.png

Select Advanced Options.

Select Bootloader Version.


Select Default for factory default settings or Latest for the latest bootloader release.

Reboot with sudo reboot.

sparkplug have you added dtparam=pciex1 to /flash/config.txt?

Spotted this in Google results: https://wiki.geekworm.com/NVMe_SSD_boot_…_Raspberry_Pi_5 which states "We recommend avoiding the following NVMe SSD drives which is equipped with a Phison controller due to their proven incompatibility:" .. and the Corsair MP600 is listed. However there are notes on the same page and posts in RPi forums that hint some devices are then working with after RPi firmware updates (and with updates from early 2024, which is some time ago now).

So three things to do:

• Update to a current LE13 nightly (these are stable)
• Update the RPi eeprom firmware to latest (can be done via LE settings add-on)
• See if adding dtparam=pciex1_gen=3 to /flash/config.txt helps

Do one thing at a time so you can see what made the difference, should it start working. If it doesn't, I'll be pointing fingers at the Phison controller and suspecting not-all issues are resolved.

EDIT: Also share the URL from "dmesg | paste" so we can see if there's something in the system log.