[rrd-users] buffers flush every midnight
tobi at oetiker.ch
Thu Oct 30 13:54:51 CET 2008
> On Thu, 30 Oct 2008 09:39:21 +0100 (CET)
> Tobias Oetiker <tobi at oetiker.ch> wrote:
> > if you have an RRA storing daily values, then this is bound to get
> > updated at midnight GMT ...
> Yes, I have. Typical rrd created like this:
> > this will use more memory as more diskblocks go to cache
> > and it will cause a lot of disk activity as the data blocks get
> > read in for the updates.
> You seem to be right... Two-hour values computation is slightly slowed
> down too. Not that critical, but noticeably.
> One unexplained thing is that 'Buffers' values decreases, but not
> 'Cached'. As far as I know, in modern kernels 'Buffers' shows amount of
> RAM allocated for file-system metadata cache and actual content stored
> in 'Cached' memory.
if you are using a 1.3 version of rrdtool it will try to tell the
kernel to NOT cache the daily values since it will not be using
them for another 24h ...
> rrd-users mailing list
> rrd-users at lists.oetiker.ch
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900
More information about the rrd-users