2005 Database Mirroring & Witness

I'm devlving into 2005 and specifically mirroring.

Having read the following article (
http://www.microsoft.com/technet/pr...5/dbmirror.mspx ),
is mirroring a sensible option as it indicates that it should not be
used in a production environment, yet the SQL2005 seminars I've been to
indicate that this is a worthy option.

Do we also need a witness server, or can this be done (sensibly) with
two SQL2005 servers ?

Currently we have 2xSQL2000 (clustered) servers and a SAN for the data.
If we go down the route of mirroring, it looks like we can get rid of
the SAN and Cluster and use the mirroring instead.

Any advice on the pro's / cons would be appreciated.

Thanks

RyanRyan,

I haven't done too much with mirroring yet but

> Do we also need a witness server, or can this be done (sensibly) with
> two SQL2005 servers ?

It is physically possible to do this with 2 servers (in fact it is
physically possible to do it on 1 server) but it really doesn't make sense.
The server can only be live if it has a quorum (2 out of 3) agree that it is
the live server. If the primary server is one machine and the second
machine contains the mirror server and the witness server both and the
second machine goes off-line you have effectively taken the primary server
off-line as well since it will no longer have a quorum.

HTH,
John|||"Ryan" <ryanofford@.hotmail.com> wrote in message
news:1142346007.542792.217730@.e56g2000cwe.googlegr oups.com...
> I'm devlving into 2005 and specifically mirroring.
> Having read the following article (
> http://www.microsoft.com/technet/pr...5/dbmirror.mspx ),
> is mirroring a sensible option as it indicates that it should not be
> used in a production environment, yet the SQL2005 seminars I've been to
> indicate that this is a worthy option.

It's worth playing with.

BUT, it's beta. Which means if you use it in a production evironment and
something goes wrong, the amount of support that MS will provide is limited.

> Do we also need a witness server, or can this be done (sensibly) with
> two SQL2005 servers ?

Generally you should have a witness.

> Currently we have 2xSQL2000 (clustered) servers and a SAN for the data.
> If we go down the route of mirroring, it looks like we can get rid of
> the SAN and Cluster and use the mirroring instead.
> Any advice on the pro's / cons would be appreciated.
> Thanks
>
> Ryan|||What do we need licence wise for the witness server ? Will we be able
to use a standard licence ?|||You can use any edition for the witness.

--
Tom

----------------
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA
SQL Server MVP
Columnist, SQL Server Professional
Toronto, ON Canada
www.pinpub.com
..
"Ryan" <ryanofford@.hotmail.com> wrote in message
news:1142422233.452068.120450@.z34g2000cwc.googlegr oups.com...
What do we need licence wise for the witness server ? Will we be able
to use a standard licence ?|||Ryan,

> What do we need licence wise for the witness server ? Will we be able
> to use a standard licence ?

The witness can be any edition of SQL Server 2005 including the free Express
Edition.

HTH,
John