does linux write cache

[Carlos]

We noticed that Linux does a lot of IO buffering/caching, I mean more
than 1 gig of RAM goes to buffers and cache according to the "free"
command. Our systems have a lot of RAM, often unused.
What we are wondering is whether that buffer/cache is write or read or
both? and if so, is there a way to turn off writing cache/buffers?

Thanks,

--Carlos

[Tauno Voipio]

Carlos wrote:
> We noticed that Linux does a lot of IO buffering/caching, I mean more
> than 1 gig of RAM goes to buffers and cache according to the "free"
> command. Our systems have a lot of RAM, often unused.
> What we are wondering is whether that buffer/cache is write or read or
> both? and if so, is there a way to turn off writing cache/buffers?
>
> Thanks,
>
> --Carlos

Linux uses free RAM for cacheing all disk traffic (except for
explicit direct I/O). The memory will be returned to the
code/data as soon as it is needed.

For details on the memory management, get the book

Understanding the Linux Kernel

published by O'Reilly.

The details are too long to be explained in a news mwssage.

--

Tauno Voipio
tauno voipio (at) iki fi