"daveberm" <david.bermingham@steeleye.com> wrote in message
news:1161871846.621466.57800@m7g2000cwm.googlegroups.com...
>I do not believe Neverfail uses Windows DFS for replication. They have
> developed their own replication engine, just like the competitors in
> this host based replication space, DoubleTake, WanSync and Steeleye.
>
> David A. Bermingham, MCSE, MCSA:Messaging
> Senior Systems Engineer
> www.steeleye.com
>
> Hilary Cotter wrote:
>> Neverfail IIRC uses Windows DFS to replicate any byte activity which
>> occurs
>> on the array, disk, folder, files you are replicating. It does work with
>> SQL
>> Server but it is termed a host based replication technology which means
>> it
>> consumes resources on your host when it is replicating - so expect some
>> (albeit a little) performance impact. The db files will be replicated to
>> the
>> standby/mirror server until you failover. Failover is not instantaneous
>> nor
>> is failback. The database files on the standby server are offline until
>> you
>> failover.
>>
>> I am referring to sql server replication where you specify which database
>> objects you wish to replicate to the destination server. The destination
>> database will be accessible after the initial snapshot is sent there and
>> it
>> will be kept synchronized with the publisher or source server with a
>> relatively low latency - seconds typically. You can select which objects
>> you
>> wish to replicate as well as a subset of the tables - ie only some
>> columns
>> or only some rows. You also have the ability to massage the data in
>> flight
>> so it looks completely different when it hits the subscriber.
>>
>> Neverfail and most other products of its ilk require their support folks
>> to
>> configure your topology and to monitor it. Surprisingly their solutions
>> are
>> quite cheap. I believe double take is well under 5k us.
>>
>> --
>> 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
>>
>> "Hardmandez" <Hardmandez@discussions.microsoft.com> wrote in message
>> news:7E081208-21B9-43D1-A241-A2B15E118575@microsoft.com...
>> > Thanks for that Hilary, some good points there. Still to get to log
>> > shipping
>> > and replication in my proposal. SQL isn't really my area of expertease
>> > so
>> > one more question, does SQL come with replication capabilities out of
>> > the
>> > box
>> > or when you talking about replication are you refering to products like
>> > Neverfail?
>> >
>> > "Hilary Cotter" wrote:
>> >
>> >> Clustering has a distance limitation. Database mirroring is not
>> >> scalable
>> >> beyond 10 or so databases but has no clustering limitation. Clustering
>> >> requires expensive hardware. Database Mirroring does not. Database
>> >> Mirroring is available on developer and Enterprise and above versions
>> >> of
>> >> SQL
>> >> Server 2005. Clustering is available on EE versions of SQL 7 and
>> >> above,
>> >> and
>> >> also on SQL Server Standard in SQL 2005.
>> >>
>> >> Database Mirroring does add some latency to each transaction and as it
>> >> is
>> >> hostbased it works best for low loads on SQL Server. If you have high
>> >> cpu
>> >> utilization your database mirroring solution is likely to fail.
>> >>
>> >> You neglect to mention log shipping and replication in your list of DR
>> >> solutions. Both of these word well as well. Log shipping does increase
>> >> your
>> >> exposure to data loss, and is not really scalable beyond a certain
>> >> size
>> >> and
>> >> number of databases. Replication replicates on an object level and has
>> >> no
>> >> limitation. Failback can be complex.
>> >>
>> >> --
>> >> Hilary Cotter
>> >> Director of Text Mining and Database Strategy
>> >> RelevantNOISE.Com - Dedicated to mining blogs for business
>> >> intelligence.
>> >>
>> >> This posting is my own and doesn't necessarily represent
>> >> RelevantNoise's
>> >> positions, strategies or opinions.
>> >>
>> >> 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
>> >>
>> >>
>> >>
>> >> "Hardmandez" <Hardmandez@discussions.microsoft.com> wrote in message
>> >> news:F2DB4016-3D90-4438-B49D-B7B4F76CE03D@microsoft.com...
>> >> > Hi,
>> >> >
>> >> > I'm writing a proposal for a DR solution for a SQL based
>> >> > application.
>> >> > I've
>> >> > been looking at clustering, database mirroring, etc. Has anyone
>> >> > come
>> >> > across
>> >> > any documentation discussing the pro's and cons of the various
>> >> > options
>> >> > available?
>> >> >
>> >> > Thanks
>> >> >
>> >> >
>> >>
>> >>
>> >>
>

"Hardmandez" <Hardmandez@discussions.microsoft.com> wrote in message
news:7E081208-21B9-43D1-A241-A2B15E118575@microsoft.com...
> Thanks for that Hilary, some good points there. Still to get to log
shipping
> and replication in my proposal. SQL isn't really my area of expertease so
> one more question, does SQL come with replication capabilities out of the
box
> or when you talking about replication are you refering to products like
> Neverfail?
>
> "Hilary Cotter" wrote:
>
> > Clustering has a distance limitation. Database mirroring is not scalable
> > beyond 10 or so databases but has no clustering limitation. Clustering
> > requires expensive hardware. Database Mirroring does not. Database
> > Mirroring is available on developer and Enterprise and above versions of
SQL
> > Server 2005. Clustering is available on EE versions of SQL 7 and above,
and
> > also on SQL Server Standard in SQL 2005.
> >
> > Database Mirroring does add some latency to each transaction and as it
is
> > hostbased it works best for low loads on SQL Server. If you have high
cpu
> > utilization your database mirroring solution is likely to fail.
> >
> > You neglect to mention log shipping and replication in your list of DR
> > solutions. Both of these word well as well. Log shipping does increase
your
> > exposure to data loss, and is not really scalable beyond a certain size
and
> > number of databases. Replication replicates on an object level and has
no
> > limitation. Failback can be complex.
> >
> > --
> > Hilary Cotter
> > Director of Text Mining and Database Strategy
> > RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
> >
> > This posting is my own and doesn't necessarily represent RelevantNoise's
> > positions, strategies or opinions.
> >
> > 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
> >
> >
> >
> > "Hardmandez" <Hardmandez@discussions.microsoft.com> wrote in message
> > news:F2DB4016-3D90-4438-B49D-B7B4F76CE03D@microsoft.com...
> > > Hi,
> > >
> > > I'm writing a proposal for a DR solution for a SQL based application.
> > > I've
> > > been looking at clustering, database mirroring, etc. Has anyone come
> > > across
> > > any documentation discussing the pro's and cons of the various options
> > > available?
> > >
> > > Thanks
> > >
> > >
> >
> >
> >

Hilary Cotter wrote:
> Hi David.
>
> Last time I spoke with Neverfail they told me they licensed their technology
> from Doubletake. You are correct about DFS and Doubletake. My mistake, DFS
> does provide very similar services to Doubletake, and in some cases DFS is a
> better choice than Doubletake (for example in file replication).
>
> --
> Hilary Cotter
> Director of Text Mining and Database Strategy
> RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
>
> This posting is my own and doesn't necessarily represent RelevantNoise's
> positions, strategies or opinions.
>
> 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
>
>
>
> "daveberm" <david.bermingham@steeleye.com> wrote in message
> news:1161871846.621466.57800@m7g2000cwm.googlegroups.com...
> >I do not believe Neverfail uses Windows DFS for replication. They have
> > developed their own replication engine, just like the competitors in
> > this host based replication space, DoubleTake, WanSync and Steeleye.
> >
> > David A. Bermingham, MCSE, MCSA:Messaging
> > Senior Systems Engineer
> > www.steeleye.com
> >
> > Hilary Cotter wrote:
> >> Neverfail IIRC uses Windows DFS to replicate any byte activity which
> >> occurs
> >> on the array, disk, folder, files you are replicating. It does work with
> >> SQL
> >> Server but it is termed a host based replication technology which means
> >> it
> >> consumes resources on your host when it is replicating - so expect some
> >> (albeit a little) performance impact. The db files will be replicated to
> >> the
> >> standby/mirror server until you failover. Failover is not instantaneous
> >> nor
> >> is failback. The database files on the standby server are offline until
> >> you
> >> failover.
> >>
> >> I am referring to sql server replication where you specify which database
> >> objects you wish to replicate to the destination server. The destination
> >> database will be accessible after the initial snapshot is sent there and
> >> it
> >> will be kept synchronized with the publisher or source server with a
> >> relatively low latency - seconds typically. You can select which objects
> >> you
> >> wish to replicate as well as a subset of the tables - ie only some
> >> columns
> >> or only some rows. You also have the ability to massage the data in
> >> flight
> >> so it looks completely different when it hits the subscriber.
> >>
> >> Neverfail and most other products of its ilk require their support folks
> >> to
> >> configure your topology and to monitor it. Surprisingly their solutions
> >> are
> >> quite cheap. I believe double take is well under 5k us.
> >>
> >> --
> >> 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
> >>
> >> "Hardmandez" <Hardmandez@discussions.microsoft.com> wrote in message
> >> news:7E081208-21B9-43D1-A241-A2B15E118575@microsoft.com...
> >> > Thanks for that Hilary, some good points there. Still to get to log
> >> > shipping
> >> > and replication in my proposal. SQL isn't really my area of expertease
> >> > so
> >> > one more question, does SQL come with replication capabilities out of
> >> > the
> >> > box
> >> > or when you talking about replication are you refering to products like
> >> > Neverfail?
> >> >
> >> > "Hilary Cotter" wrote:
> >> >
> >> >> Clustering has a distance limitation. Database mirroring is not
> >> >> scalable
> >> >> beyond 10 or so databases but has no clustering limitation. Clustering
> >> >> requires expensive hardware. Database Mirroring does not. Database
> >> >> Mirroring is available on developer and Enterprise and above versions
> >> >> of
> >> >> SQL
> >> >> Server 2005. Clustering is available on EE versions of SQL 7 and
> >> >> above,
> >> >> and
> >> >> also on SQL Server Standard in SQL 2005.
> >> >>
> >> >> Database Mirroring does add some latency to each transaction and as it
> >> >> is
> >> >> hostbased it works best for low loads on SQL Server. If you have high
> >> >> cpu
> >> >> utilization your database mirroring solution is likely to fail.
> >> >>
> >> >> You neglect to mention log shipping and replication in your list of DR
> >> >> solutions. Both of these word well as well. Log shipping does increase
> >> >> your
> >> >> exposure to data loss, and is not really scalable beyond a certain
> >> >> size
> >> >> and
> >> >> number of databases. Replication replicates on an object level and has
> >> >> no
> >> >> limitation. Failback can be complex.
> >> >>
> >> >> --
> >> >> Hilary Cotter
> >> >> Director of Text Mining and Database Strategy
> >> >> RelevantNOISE.Com - Dedicated to mining blogs for business
> >> >> intelligence.
> >> >>
> >> >> This posting is my own and doesn't necessarily represent
> >> >> RelevantNoise's
> >> >> positions, strategies or opinions.
> >> >>
> >> >> 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
> >> >>
> >> >>
> >> >>
> >> >> "Hardmandez" <Hardmandez@discussions.microsoft.com> wrote in message
> >> >> news:F2DB4016-3D90-4438-B49D-B7B4F76CE03D@microsoft.com...
> >> >> > Hi,
> >> >> >
> >> >> > I'm writing a proposal for a DR solution for a SQL based
> >> >> > application.
> >> >> > I've
> >> >> > been looking at clustering, database mirroring, etc. Has anyone
> >> >> > come
> >> >> > across
> >> >> > any documentation discussing the pro's and cons of the various
> >> >> > options
> >> >> > available?
> >> >> >
> >> >> > Thanks
> >> >> >
> >> >> >
> >> >>
> >> >>
> >> >>
> >