CHAPTER 4 The UNIX File System
As operating systems grew in size, and this was especially noticeable in the transition to Solaris, more files, and more changing files, were placed in the root partition. For example, by default the Solaris install put /var in root, but /var now changes considerably every time you add a new software package or install an OS patch. So the old idea of a small, little-changing root partition doesn't hold, unless you separate /var on another partition.
There has been a lot of discussion of this topic in the system administration newsgroups recently. For standalone machines it's probably most efficient to just have two partitions: one for swap, and one for everything else. For servers it's better to isolate the different types of files on separate partitions. Below I'll summarize many of the arguments for and against the two positions.
|Argument||Separate Partitions||Combined Partitions|
|Proper Size||Difficult to maintain||No maintenance|
|Tape Backups||Easier with smaller partitions||Higher density tapes, stackers|
|Small Root Partition||Less chance of corruption||Can rebuild the OS quickly|
|Any Corrupted Partition||Can more easily restore that file system||Can boot diskless & rebuild the OS quickly|
|NFS File Service||Allow different mount options||One mount option|
|Quotas||Separate quotas by partition||One quota|
|Space||Can run out of space on one partition while lots of space on others||Still has space available to users|
|Runaway Programs||Fills space only on that partition||Fills all available space, this may shut down essential services, e.g. mail & logs|