Re: Truly High Available?

Edwin is right, an MNS cluster is the perfect solution for you.
MNS does NOT need a shared disk like a classic cluster does. An MNS cluster
would have at least 1 node on each site with mirrored SAN disks. The data &
logs would be on the SAN disks being constantly mirrored between sites, only
the active node disks would be accessible. A script running as a clustered
resource in the SQL instances cluster group would control the "failover" of
the SAN disks. The EMC or Hitachi both provide this type of solution.
Withy an MNS cluster you can also have a Fileshare Witness to provide a
majority in place of a 3rd server, ideally on a 3rd site, but not necessarily.
Iain



"Edwin vMierlo [MVP]" wrote:

Not if you use a Geographically Dispersed Cluster

As Linchi Shea already mentioned an example would be SRDF/CE for MSCS which
is a product from EMC, which works with EMC SRDF solutions.

It will be a true Failover Cluster in the sense of MSCS, but it will run
from two disk subsystems.
In short the SRDF/CE for MSCS software "fools" the cluster, thinking that it
is running on only one subsystem.
When a failover occurrs, the SRDF/Ce for MSCS will failover to the other
disk subsystem prior to the cluster bringing the disks online on the other
node.

please talk to your storage vendor and ask them if they have a
Geographically Dispersed Cluster solution for you

rgds,
Edwin.


"acmcdba68" <acmcdba68@xxxxxxxxxxx> wrote in message
news:878901AE-CBE5-44FE-A4F0-7B0A312E2F16@xxxxxxxxxxxxxxxx
Again,

The failover clustering would entail a shared disk subsystem correct? It
would also entail re-coding the application connection strings
"multi-threaded" urgh !!!

Has anyone looked at CA's\XOsoft's WANSync HA?

Thx,
--
Anthony E. Castro - MCDBA


"acmcdba68" wrote:

I have a scenerio where I must implement a Highly Available environment
between two locations seperated by 25 miles.

The premise is to create a solution that will keep our application up
and
running if our main location were hit by a tornado, an auto failover
would
take place to the remote location.

If using a Microsoft Clustered solution, how is it truly 'HA' if there
is a
shared disk sub-system? If there is a tornado in Loc 'A' and the shared
disk
resides there, what have I accomplished? The same goes for Loc 'B'?

Maybe I'm reading more into it but would like someone to shed some light
on
this.
--
Anthony E. Castro



.

Relevant Pages

  • Daily Report #4165
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  • Re: Configure failover in seconds
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    (microsoft.public.windows.server.clustering)
  • changed WWID on cluster member boot disk
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  • Re: Clustering Newbie - SAN Advice
    ... A SAN generally has gigabtes of cache and uses large internal block sizes ... The SAN or Smart array will dictate what internal connection the disks have. ... Senior SQL Infrastructure Consultant ... single-instance cluster. ...
    (microsoft.public.sqlserver.clustering)