Not enough space in the /boot partition

You are preparing an upgrade for a R77.X gateway to R80.10 and suddenly a verify action in CPUSE gives you this result:

Verifier results 
Package: R80.10 Fresh Install and Upgrade from R7X 
Clean Install:
There is not enough disk space for installation - 
Not enough space in the /boot partition : Available: 0.00 MB Required: 15 MB

Upgrade:
There is not enough disk space for installation - 
Not enough space in the /boot partition : Available: 0.00 MB Required: 15 MB 

When issuing Expert command df -h you’ll notice that /boot is 100% in use which means you have 0MB left of the 145MB. What can be the issue here?

It might be worth taking a look at how many snapshots you have on your system. Take a look at this CLISH example:

SOMEDEVICE:0> show snapshots
Restore points:
JHF225
PRE_JHF351
JHF
STAGING
PROD
PRE_UPGRADE
ROLLBACK
JHF2
PRE_R80.10

Creation of an additional restore point will need 14.240G
Amount of space available for restore points is 112.14G

In this example there are 9 snapshots and we have 112.14GB available on the device for new snapshots.

When you take a look at the /boot directory you’ll notice that there are directories with the same name as the snapshots and each of them takes up 14MB of space of the /boot partition. The snapshots are filling up the /boot partition too.

This issue is easy to resolve by deleting all the old snapshots via CLISH you’ll never revert to. Do not delete the directories manually from Expert mode but use the CLISH command delete snapshot <name of snapshot> . This way you free up the /boot partition and you will be able to successfully verify and upgrade with CPUSE.

Credits go to my colleague Nick who encountered the issue and fixed it.