With previous generation of Check Point UTM appliances (so called UTM-1 which included UTM 132, 270, 450 etc.) it was a really nagging issue when firewall run out of space on its hard disk. It was especially problematic for the root partition cause it is used for update downloads, upgrade files etc. It is less of a problem today as Check Point folks made root partition by default much bigger than the old UTM-1 one, still from time to time you may need to increase root or some other partition to add free space to the firewall. As Check Point is a Linux in disguise to do so is actually easy using native Linux tools . Fortunately UTM appliances come with quite a bit of Unallocated space you can see with fdisk -l. This unallocated space is used to store images for factory reset in case of need so do not go wild using it up. For resizing to take effect you will have to reboot the firewall afterwards. Here are commands to be run in expert mode: Let's say I want to add 15 Gb to the root partition:
Checkpoint# lvresize -L 15GB vg_splat/lv_current
Checkpoint#  resize2fs /dev/mapper/vg_splat-lv_current
That is it . BTW Officially, it is not supported by Checkpoint to modify the size of partitions / file systems on Check Point appliances. Still, many times I've done it I didn't experience any issues, but be aware.