CentOS - Apr 2006 - Preventing the nightly backup from disturbing the cache

Hi all,

I have a server with 4GB of memory and a workload that allows it to work 
mostly from memory without a lot in the way of disk reads.  However, 
every night the backup distrurbs that situation by reading every file on 
the system.

Is there a way to prevent this from happening?  I'd like to be able to 
tell the kernel, hey this program is going to be reading a bunch of 
files serially, so please don't cache the data.

Is that possible?

Thanks,
Steve

Steve Bergman wrote:
> Hi all,
> 
> I have a server with 4GB of memory and a workload that allows it to work 
> mostly from memory without a lot in the way of disk reads.  However, 
> every night the backup distrurbs that situation by reading every file on 
> the system.
> 
> Is there a way to prevent this from happening?  I'd like to be able to 
> tell the kernel, hey this program is going to be reading a bunch of 
> files serially, so please don't cache the data.
> 
> Is that possible?
I haven't found anything but that would be a nice feature when dealing 
with a ton of data that would only need to be accessed once(like large 
backups or large file conversions.

I am rather surprised that this has not been dealt with by now.  Why 
mess with the currently cached information when you know that the files 
being read will be many times more than your memory/swap space and will 
only need to be read once.