If you type
:set history, you'll see the number of
: entires that will be stored. The default is
20, which is what my Vim is set to. However, you can easily set it to anything: I've seen vimrc files on GitHub with it set to
History includes previous search patterns as well as command-line entries. These are written to the
.viminfo file. You can change which file Vim reads for
.viminfo by using the
-i switch when starting Vim, and if you use
-i NONE you can start Vim without a viminfo file, which can be useful if you're trying to work out strange behaviour between sessions, or if Vim is starting up slowly.
These days disks are fast enough that a large viminfo shouldn't cause much of a slowdown, so you may find it useful to increase
'history' beyond the default of 20.