Questions[var](server)

First question:

When I run df -h I can see this:

# df -h
Filesystem     Size    Used   Avail Capacity  Mounted on
/dev/ad4s1a    9.7G    8.0G    918M    90%    /
devfs          1.0K    1.0K      0B   100%    /dev
/dev/ad4s1d    1.8T    6.7G    1.6T     0%    /home
procfs         4.0K    4.0K      0B   100%    /proc
linprocfs      4.0K    4.0K      0B   100%    /usr/compat/linux/proc
devfs          1.0K    1.0K      0B   100%    /var/named/dev

Why doesnt it show directories like:

/var /etc /usr

? On my earlier dedicated server, I was able to view every partition size available, but here I got only /home and /...

Second question:

How I can increase the /var partition size? Because after 2 hours of working, this partition is became full...

Is it possible to restore the functionality of /var/lib/apt/lists and /var/apt/cache after deleting them or minmizing them in some wa

I am trying to shrink down an Ubuntu VM to the smallest size and decided to delete /var/lib/apt/lists and /var/cache/apt with the intention of restoring them when the system needs to be updated. I have done /var/cache/apt without major side effects, simply recreating some directories reenables it. The /var/lib/apt/lists is the one I am unsure of. Is it possible delete it and restore its functionality by recreating like /var/cache/apt?

Does doing that destroy the knowledge apt and dpkg have of the systems configuration or is that stored elsewhere?

I currently only have remote access to this CentOS box, I need to move /var form the primary RAID to a new set of disks that was installed with more space, My current thoughts on how to accomplish this is to temporarily mount the new RAID to /tmp/var. rsync everything from /var to /temp/var then modify the fstab to point /var at the new disks.

Here is my question. how do I delete the existing /var on the primary disks once I have the new disks mounted to that location (assuming this is even possible remotely)?

I'm trying to delete /var/www/html but I'm getting this error:

rm: cannot remove `html': Device or resource busy

Are MySQL databases always stored in /var on CentOS?

Specifically - If a new CentOS/cPanel server that needs to support MySQL, doesn't have that partition, but only has these, does that mean MySQL data is somehow being stored in a temporary dump somewhere?

/dev/sda3              /
tmpfs                  /dev/shm
/dev/sda1              /boot
/usr/tmpDSK            /tmp