File Read Cache - How to purge?

[Hrvoje Niksic]

Nick Craig-Wood <nick at craig-wood.com> writes:

>> >   http://www.linuxinsight.com/proc_sys_vm_drop_caches.html
>> 
>>  That URL claims that you need to run "sync" before dropping the cache,
>>  and so do other resources.  I wonder if that means that dropping the
>>  cache is unsafe on a running system.
>
> It isn't unsafe, the OS just can't drop pages which haven't been
> synced to disk so you won't get all the pages dropped unless you
> sync first.

Thanks for the clarification.