[rrd-users] Re: Who has the most RRD files (or data sources)?

[Jason Fesler]

> Does this boil down to meaning that the parts of a single RRD file are
> physically close to each other on disk?  And that multiple RRD files are
> further apart?  I can see how that would make things a bit faster or slower
> but it doesn't seem like it would make the huge difference that some people
> seem to see when they put multiple RRAs into one RRD.

man truss
man strace

Whatever one works, please use it, and look for seek/read/write calls.

> Am I just clueless? :)  Or does it make sense to you that the difference is
> huge?

Yes, and yes.

Each RRD update involves seek/read/seek/write the header, and seek/write 
once per RRA.  Doesn't matter (realistically) how many DS's there are for 
that update.

rrd_update.c is the authoritice source on what really happens under the 
hood, but strace/truss and the like can also give you a view of what is 
happening - without having to know C.


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