This article describes about how to recover if the device is stuck in loader prompt with a log " can't load kernal".
Below logs are seen on the console:
ata_build_rw_tf: Error: sectors = 0!
Error building rw taskfile
[1]Booting from SSD slice 1
1.Try multiple reboots.
Even after the reboots, if it is still stuck on loader prompt, try the below methord:
2.Recovering from loader prompt:
> Hard reboot the firewall.
> During the reboot, following message is displayed
Hit [Enter] to boot immediately, or space bar for command prompt.
> Press the space bar continuously to get the loader prompt.
> Once you see loader prompt "loader>" then apply then perform the below:
Format the USB in fat32 format.
Download the Junos image and copy it to the USB.
Plug the usb to the device.
Enter the below command on the loader prompt of SRX:
Loader>install file:///<package_name.tgz-on USB> and hit enter.
Performing the above should take the device to the login prompt, if not alternatively you can try the below method:
3.If you have a healthy same model device, then take snapshot from the device:
Plug the USB and run "request system snapshot media usb". Once it is completed, unmount the USB and connect it to the faulty device and reboot.
Now the device tried to boot from the USB.
Once you are able to login , then run the following command "request system reboot media internal" and unmount the USB.