[Gllug] Embedded Linux & 1Gbps?

[Thomi Richards]

On 10/17/07, Nix <nix at esperi.org.uk> wrote:
> I've noticed it, but only when throwing gigabytes around.
>
> For normal I/O, and especially for things like find(1), the delay is on
> the disk end. I know my 100Mb/s network can throw data around somewhat
> faster than the RAID-5 array backing its NFS-mounted drives can read or
> write data. (Maybe much faster disks could fix this, but the PCI bus
> isn't all that terribly fast itself...)
>

Why is that though? Surely the data transfer rate should be constant,
no matter what the file size?

For example, when streaming a large movie over NFS, if I seek to half
way though the movie, it takes *ages* - surely NFS doesn't try and
transmit the entire first half of the file?  Although I guess this
might have more to do with the way the movie player is written rather
thant he disk protocol, right? I always assumes that mplayer (and
others) just did a seek() call to get to the right place in the file,
but I guess that would depend on the file format (many media formats
aren't that simple)..


Anyway, cheers for the advice.
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