On Sunday 16 March 2008 23:49, david@lang.hm wrote:
quoted text
> > Mirroring on the other hand, makes a realtime copy of a volume, that is
> > never out of date.
> 
> so just mirror to a local disk array then.

Great idea.  Except that the disk array has millisecond level latency,
when what we trying to achieve is microsecond level latency.

quoted text
> a local disk array has more write bandwidth than a network connection to a 
> remote machine, so if you can mirror to a remote machine you can mirror to 
> a local disk array.

So you could potentially connect to a _huge_ disk array and write deltas
to it.  The disk array would have to support roughly 3 Gbytes/second of
write bandwidth to keep up with the Violin ramdisk.  Doable, but you are
now in the serious heavy iron zone.

Personally, I like my nice simple design a lot more.  Just mirror it, as
many times as you need to satisfy your paranoia.  Or how about go write
your own?

Daniel
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