[Dclug] Question about Speed: data transmission vs write-to-disk

[Ben Colombini]

Read up on RAID:
http://en.wikipedia.org/wiki/RAID

In short, there are different ways of setting up a raid to gain 
different benefits of combinations of benefits.
Striping will allow the faster writing you were asking about (performance).
Mirroring provides the redundancy that RAID is best known for (safety).
RAID has nothing to do with security, as the RAID array will obey 
malicious commands just as a single disk would.

Regarding your more theoretical question, while I don't know how 
hardware at big hubs/hops works, while HDD may increasingly be slower 
than net speed, a computer doesn't need to record everything that comes 
in from the net to the disk.  Much of the data may be used, refined, 
discarded, or sent back out rather than being written to disk.

If one really did want to permanently record everything that goes 
through a major hub/hop, I'd imagine they would be in for quite a 
technical and legal challenge.

Ben Colombini
DC PHP
Phone: 703-535-6890
Fax:   703-683-2888
ben at dcphp.com



Alan McConnell wrote:
> Assembled Wisdom!
>
> I hope this is not considered OT; it is somewhat theoretical.
>
> Data, over very fast trunk routers, comes at one very fast, what
> with frequence of light carrier waves, and ever-increasing modulation
> technology.  If the output of some such pipe has to be written
> to disk, can the writing to disk keep up?  Will it always be
> able to?
>
> My thought:  RAID has, in my hearing, always been discussed as a
> security/safety measure, so that data can be recovered even in case
> of a disk crash.  But are writes to a RAID system, by say a multi-processor
> machine, faster than straight writes to a single disk?
>
> Any thoughts much appreciated; extra credit for detailed knowledge!<G>
>
> Best wishes,
>
> Alan
>
>