On a database system; only the Oracle software installed on /u01 (80GB) and therefore it does not require a lot of space ie. CHARON:

[UNDEF]-oracle@charon:~$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda3              91G   14G   73G  16% /
tmpfs                  16G  9.9M   16G   1% /dev/shm
/dev/sda1             190M  142M   39M  79% /boot
/dev/mapper/data-u01  197G   41G  146G  22% /u01
/dev/mapper/data-u02  591G  224G  338G  40% /u02
/dev/mapper/data-u03  296G   99G  183G  36% /u03
/dev/mapper/data-l01  9.8G  3.1G  6.2G  33% /l01
/dev/mapper/data-l02  9.8G  3.1G  6.2G  33% /l02
/dev/mapper/data-l03  148G   11G  130G   8% /l03
/dev/mapper/data-l04  9.8G   23M  9.2G   1% /l04
/dev/mapper/data-l05  197G   45G  142G  25% /l05
/dev/mapper/data-l07   79G   50G   25G  67% /l07

In general, the database vm systems only requires the following partitions:

/u01 - oracle software (80GB)
/u02 - data files (small - 100GB, medium - 200GB, large - 350GB) ****
/u03 - data files - indexes (medium - 150GB, large - 300GB) ****
/l01 - control file (15GB)
/l02 - control file (15GB)
/l03 - archive logs if enabled (100GB) ****
/l04 - no longer used
/l05 - backups (200GB or more based on /u02)
/l06 - no longer used
/l07 - software repository (250GB)

*** systems hosting multiple databases needs to be adjusted accordingly
**** should scale-up from reserves; CHARON is an anomaly because of the ITEC standby database

The setup is very different for application servers.