Messages in this thread | | | Date | Mon, 17 Mar 2008 07:42:59 -0700 (PDT) | From | david@lang ... | Subject | Re: [ANNOUNCE] Ramback: faster than a speeding bullet |
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On Mon, 17 Mar 2008, Daniel Phillips wrote:
> On Sunday 16 March 2008 23:49, david@lang.hm wrote: >>> 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 never out of date.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. > >> 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.
your network will do less then 1 Gbit/sec, so to mirror in real-time (what you claim is trivial) you would need at least 24 network connections in parallel. that's a LOT harder to setup then a high performance disk array.
David Lang
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