First, nomenclature: these are not partitions. These are filesystems that have been created on logical volumes. The logical volumes are carved out of volume groups, which themselves are built from block devices -- which may be partitions, or may simply be entire disks.
Having "large" filesystems is not by itself a problem. I put "large" in quotes because 43GB isn't particularly big. Multiple terabytes is "large" where I come from, so it all depends on your perspective.
If your filesystems are growing fast enough that you find yourself frequency resizing it, then you may have a problem:
You may have simply created the filesystem too small to begin with. In this case, you should at some point figure out what size it needs to be and things should stabilize.
You may have something that is erroneously using up disk space. Something logging too verbosely can do this, as can something logging to a file that nevers gets rotated. You can use tools like
du to investigate where disk space is being used.
You may simply be running services that as part of their normal operating consume additional disk space. Web sites with user-submitted content, email servers, databases, and other such services will tend to grow over time. Your job in this case is to figure out how fast things are growing and plan your storage expansion appropriately.
Without knowing (a) what services you're running and (b) what's causing the space to be consumed, we can't really provide any guidance on what represents an appropriate size and how to address the growth.
You can use
du to find the space consumed by a paritcular directory like this:
# du -sh /var/lib
-s gives you a grand total, and
-h gives you "human-readable" sizes (e.g., "21G" instead of "21998608".