caveats for synchronous hardware based replication?

Hello,
Thinking about synchronous hardware based mirroring using EMCs clariion
product line over a dedicated fiber connection between two geographically
separate data centers. I realize that there is a basic speed of light issue
here regarding the distance I can have between the two sites and still keep
my servers synched real-time.
Would someone please shed some more light on what is involved here? What's
the maximum distance I can have betwen these sites and why? Any other
caveats with this setup I should be aware of? Thanks.
BTW - running an OLTP environment SQL2000.
I don't believe that these solutions are truly synchronous, and second its
way slower than the speed of light.
The most significant factors are price and skill set required. If you think
replication is tough wait till you get behind EMC's SRDF.
Hilary Cotter
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602.html
Looking for a FAQ on Indexing Services/SQL FTS
http://www.indexserverfaq.com
"mb" <mb@.discussions.microsoft.com> wrote in message
news:8AB9A09B-325B-4A59-9C54-1CC65BD1348B@.microsoft.com...
> Hello,
> Thinking about synchronous hardware based mirroring using EMCs clariion
> product line over a dedicated fiber connection between two geographically
> separate data centers. I realize that there is a basic speed of light
issue
> here regarding the distance I can have between the two sites and still
keep
> my servers synched real-time.
> Would someone please shed some more light on what is involved here?
What's
> the maximum distance I can have betwen these sites and why? Any other
> caveats with this setup I should be aware of? Thanks.
> BTW - running an OLTP environment SQL2000.
|||I'm curious why you state the hardware mirroring is not truly synchronous?
It was my understanding that if distances were kept under a certain limit
then this solution could be considered to be essentially synchronous.
Oh, just got your replication book Hilary - great read!
"Hilary Cotter" wrote:

> I don't believe that these solutions are truly synchronous, and second its
> way slower than the speed of light.
> The most significant factors are price and skill set required. If you think
> replication is tough wait till you get behind EMC's SRDF.
> --
> Hilary Cotter
> Looking for a SQL Server replication book?
> http://www.nwsu.com/0974973602.html
> Looking for a FAQ on Indexing Services/SQL FTS
> http://www.indexserverfaq.com
> "mb" <mb@.discussions.microsoft.com> wrote in message
> news:8AB9A09B-325B-4A59-9C54-1CC65BD1348B@.microsoft.com...
> issue
> keep
> What's
>
>
|||My understanding from EMC is that there are two modes. 1) Synchronous and 2)
asynchronous.
In the Synchronous mode, data is written to the source and the app receives
the commit. Then under the covers the write is written to the destination.
So, its not a true split write. Asynchronous has queuing built in.
Let me check with my EMC rep and confirm this.
Glad you like the book!
Hilary Cotter
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602.html
Looking for a FAQ on Indexing Services/SQL FTS
http://www.indexserverfaq.com
"mb" <mb@.discussions.microsoft.com> wrote in message
news:1910F129-8553-42BA-BD15-8B8517D9BC0B@.microsoft.com...[vbcol=seagreen]
> I'm curious why you state the hardware mirroring is not truly synchronous?
> It was my understanding that if distances were kept under a certain limit
> then this solution could be considered to be essentially synchronous.
> Oh, just got your replication book Hilary - great read!
> "Hilary Cotter" wrote:
its[vbcol=seagreen]
think[vbcol=seagreen]
clariion[vbcol=seagreen]
geographically[vbcol=seagreen]