Do you mean the partition the LVM volumes live on?
That is correct. Under SDA I have SDA1 which is where all the grub stuff resides and SDA2 where I have the lv_root and lv_swap volumes. That SDA2 partition is 99G.
@tessierp: DANGER ZONE
Normally I would make sure I know the start and end sector of the partition fdisk -l /dev/sda and write those numbers to a file fdisk -l /dev/sda > partitions or even make a backup of the hole MBR booted from a recovery USB dd if=/dev/sdX of=backup-sdX.mbr bs=512 count=1
Then delete with the partition in fdisk and recreate it with the exact same type, start sector and the minimal size plus headroom to be save (ie total +42G in your case)
Do not know if a Linux LVM partition survives thisā¦
(Hence with all the benefits XFS may have, I hate it)
I would say it probably doesnāt survive since it needs to be attached to a driveā¦
I totally agree there, I never had so much trouble before with a filesystem. I really do not like XFS and I hope the next version of Nethserver gives us an option to install another FS. Or is it possible and I just didnāt pay attention? 
It is CentOS, so Nethsever, default. For nethsever-installs I keep the default.
If I install a CentOS VM for development (which are throw-away VMās) tend to partition manually with good old ext4; simply because resizing is easy. 