How much memory is free?

Display amount of free and used memory in the system

user1@deby:~$ free -m
             total       used     free   shared  buffers   cached
Mem:           377         61      315        0       30       16
-/+ buffers/cache:         14*     362**
Swap:         1105          0     1105

14* - the amount of physical memory the system is using right now
362** - actually free.

File system disk space usage

user1@deby:~$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             327M   89M  222M  29% /
tmpfs                 189M     0  189M   0% /lib/init/rw
udev                   10M  604K  9.5M   6% /dev
tmpfs                 189M     0  189M   0% /dev/shm
/dev/sda9              11G  156M  9.9G   2% /home
/dev/sda8             373M   11M  343M   3% /tmp
/dev/sda5             4.6G  397M  4.0G   9% /usr
/dev/sda6             2.8G  145M  2.5G   6% /var