- to separate or support different file systems for system and user data.
- protect critical partitions from running out of disk space.
- to work around 16/32-bit BIOS limitations.
Partitions do not:
- distribute the risk of data loss due to disk failures.
- distribute the I/O workload to separate controllers or disks.
Required for PC Linux as in absolutely necessary is only one:
Required as in reasonable are 3:
This is the default.
If you want to get fancy and protect (root) from running out of disk space and create partitions for log files and have other users than root in your system, you can usually get along with the following additional partitions:
Everything else is most likely nonsense unless you have to deal with disks that are 200 MB. It is generally a good idea to use a small amount of partitions as possible, in particular if you cannot estimate the maximum required size and usage. Considering the large sizes of disks available today the benefit of not limiting space usage by partitions is often higher than possible protection from bad processes.
If you have a PC with a PC-BIOS you need a Master Boot Record (MBR). In which case each hard drive is limited to a maximum of 4 primary partitions, or 3 primary partitions and one extended partition with any number of logical partitions. If you have PC with EFI and GPT than you can have up to 128 primary partitions.