OK here's some nuts and bolts. /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>
UUID=fd099c81-9f23-41d3-a607-00349d56bf3b /Data/Ben ext4 defaults,noatime 0 2
UUID=6cf3f5f6-b68c-431f-85ff-54081c8706eb /Data/Tommy ext4 defaults,noatime 0 2
UUID=76CD-D1A2 /boot vfat defaults,noatime 0 2
UUID=98fbffd0-9ee5-4d12-9cab-fd5060cc12f2 / ext4 defaults,noatime,discard 0 1
UUID=2add371d-67e2-4408-a0a8-c9adc5cf7af8 /home ext4 defaults,noatime,discard 0 2
UUID=4f90b2ee-a5d9-4b40-ba90-49ee9315999b swap swap defaults,noatime,discard 0 0
UUID=150e6583-3d06-4aa5-b39d-767703b11bf7 /Data1 ext4 defaults,noatime,discard 0 2
tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0
And fdisk -l:
# fdisk -l
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes, 1953525168 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
Disk label type: gpt
# Start End Size Type Name
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes, 1953525168 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
Disk label type: gpt
# Start End Size Type Name
1 2048 976764927 465.8G Linux filesyste
2 976764928 1953523711 465.8G Linux filesyste
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
Disk /dev/sdc: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 821247 400M EFI System
2 821248 42764287 20G Linux filesyste
3 42764288 63735807 10G Linux filesyste
4 63735808 105678847 20G Linux filesyste
5 105678848 126650367 10G Linux filesyste
6 126650368 168593407 20G Linux filesyste
7 168593408 189564927 10G Linux filesyste
8 189564928 231507967 20G Linux filesyste
9 231507968 252479487 10G Linux filesyste
10 252479488 294422527 20G Linux filesyste
11 294422528 315394047 10G Linux filesyste
12 315394048 357337087 20G Linux filesyste
13 357337088 378308607 10G Linux filesyste
14 378308608 420251647 20G Linux filesyste
15 420251648 441223167 10G Linux filesyste
16 441223168 483166207 20G Linux filesyste
17 483166208 504137727 10G Linux filesyste
18 504137728 514623487 5G Linux swap
19 514623488 976773119 220.4G Linux filesyste
/dev/sda is at the moment unused, /dev/sdb is used for data storage, all operating system partitions, /boot/efi, and swap are on /dev/sdc.
Edit: I can do another install tomorrow and provide logs for 'sudo calamares -d'. Also /dev/sdc is an SSD.