There was a day when a 10 gb partition seemed like plenty of space to leave for the system but now it's not. An upgrade to Stretch appears to need more.
~# fdisk -l
Disk /dev/sda: 149.1 GiB, 160041885696 bytes, 312581808 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0007c9ed
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 19531775 19529728 9.3G 83 Linux
/dev/sda2 19533822 312580095 293046274 139.8G 5 Extended
/dev/sda5 19533824 27578367 8044544 3.9G 82 Linux swap / Solaris
/dev/sda6 27580416 312580095 284999680 135.9G 83 Linux
$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
# / was on /dev/sda1 during installation
UUID=f2959403-fb9c-4e56-adbf-e5b7c1f63dd8 / ext3 errors=remount-ro 0 1
# /home was on /dev/sda6 during installation
UUID=274b606c-c556-47cb-8db3-2733b7adac3f /home ext3 defaults 0 2
# swap was on /dev/sda5 during installation
UUID=5642269c-ada4-4466-a516-4a2360ee0ec1 none swap sw 0 0
This must be a FAQ. But there appear to be two ways forward.