When iso testing the current daily Lubuntu iso file (dated 2020-09-11),
I notice that a third partition is created (during the boot process),
but no file system is recognized by lsblk -f, and it is not used for
logging (as we are used to from Focal and previous versions of Groovy).

After cloning:

$ lsblk -fm /dev/sdc
NAME   FSTYPE  LABEL               UUID                                 MOUNTPOINT  SIZE OWNER GROUP MODE
sdc    iso9660 Lubuntu 20.10 amd64 2020-09-11-01-36-50-00                          55,9G root  disk  brw-rw----
├─sdc1 iso9660 Lubuntu 20.10 amd64 2020-09-11-01-36-50-00                           1,8G root  disk  brw-rw----
└─sdc2 vfat    ESP                 6903-0707                                        4,9M root  disk  brw-rw----

After booting:

lubuntu@lubuntu:~$ lsblk -fm
NAME        FSTYPE   FSVER            LABEL               UUID                                 FSAVAIL FSUSE% MOUNTPOINT               SIZE OWNER GROUP MODE
loop0       squashfs 4.0                                                                             0   100% /rofs                    1.6G root  disk  brw-rw----
sda         iso9660  Joliet Extension Lubuntu 20.10 amd64 2020-09-11-01-36-50-00                                                      55.9G root  disk  brw-rw----
├─sda1      iso9660  Joliet Extension Lubuntu 20.10 amd64 2020-09-11-01-36-50-00                     0   100% /cdrom                   1.7G root  disk  brw-rw----
├─sda2      vfat     FAT12            ESP                 6903-0707                                                                    4.9M root  disk  brw-rw----
└─sda3                                                                                                                                54.2G root  disk  brw-rw----
sdb                                                                                                                                     15G root  disk  brw-rw----
└─sdb1      vfat     FAT32            KEEP_ME             696C-99AC                               3.4G    77% /media/lubuntu/KEEP_ME  14.9G root  disk  brw-rw----
sr0                                                                                                                                     11M root  cdrom brw-rw----
zram0                                                                                                         [SWAP]                 962.2M root  disk  brw-rw----
zram1                                                                                                         [SWAP]                 962.2M root  disk  brw-rw----
zram2                                                                                                         [SWAP]                 962.2M root  disk  brw-rw----
zram3                                                                                                         [SWAP]                 962.2M root  disk  brw-rw----
nvme0n1                                                                                                                              238.5G root  disk  brw-rw----
├─nvme0n1p1 vfat     FAT32            SYSTEM_DRV          DC84-9DFC                                                                    260M root  disk  brw-rw----
├─nvme0n1p2                                                                                                                             16M root  disk  brw-rw----
├─nvme0n1p3 ntfs                      Windows-SSD         5A20850E2084F1F5                                                           134.8G root  disk  brw-rw----
├─nvme0n1p4 ntfs                      WINRE_DRV           92A48570A485579D                                                            1000M root  disk  brw-rw----
└─nvme0n1p5 ext4     1.0                                  a1aef422-8e35-4ea8-9e66-98017fa4b996                                       102.4G root  disk  brw-rw----
lubuntu@lubuntu:~$