"The nocache tool tries to minimize the effect an application has on the Linux file system cache. This is done by intercepting the open and close system calls and calling posix_fadvise with the POSIX_FADV_DONTNEED parameter. Because the library remembers which pages (ie., 4K-blocks of the file) were already in file system cache when the file was opened, these will not be marked as "don't need", because other applications might need that, although they are not actively used (think: hot standby). Use case: backup processes that should not interfere with the present state of the cache."
is an essential tool for any Linux commandline user. It's on par with
And of course it's there in most linux distro repositories. For Ubuntu just execute
apt-get install nocache
and you're clear to go. It's a shame this utility didn't get into the basic Ubuntu desktop installation.