Re: Clustering with 2 active nodes and 1 passive node

Hi

Most high end SAN's have a block level copy mechanism so that you can
"mirror" that data to another SAN, preferably at another location.
EMC has SRDF that can run synchronous or asynchronous over fast WAN links.

Tape backups must never be forgotten either.

Regards
--------------------------------
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland

IM: mike@xxxxxxxxxxxx

MVP Program: http://www.microsoft.com/mvp

Blog: http://www.msmvps.com/epprecht/

"michael wiederhold" <michael@xxxxxxxxxxxxxxx> wrote in message
news:%23RhSzuztFHA.3068@xxxxxxxxxxxxxxxxxxxxxxx
> Very helpful. Question: So now, even with RAID 10, the single point of
> failure becomes the shared drive array? How does one go about creating a
> failover for this?
>
> Respectfully,
>
> Michael Wiederhold
> michael@xxxxxxxxxxxxxxx
>
> "Mike Epprecht (SQL MVP)" <mike@xxxxxxxxxxxx> wrote in message
> news:%230j6BCZtFHA.3236@xxxxxxxxxxxxxxxxxxxxxxx
>> Hi
>>
>> You don't need a 1:1 relationship between nodes.
>> And forget the terms active / passive, it is totally out of date and does
>> not describe SQL Server 2000/2005 clustering.
>>
>> You have an instance of SQL Server running on an node.
>> If you have 2 nodes, it could run on any of those nodes at any one time.
>> If you had 3 nodes, it could run on any of those nodes, at any one time.
>> If you have 2 nodes, one sits around waiting for a failover. If you have
>> 3 nodes, 2 sit around waiting for a failover.
>>
>> If you have more than one SQL Server instance running on the cluster,
>> then the instances can run on any of the nodes.
>> The instances could be all running on the same node, or dispersed over
>> the various nodes.
>>
>> Quite often, people run with 3 nodes and 2 instances or 4 nodes with 3
>> instances. There is nothing stopping you running 3 instances on 3 nodes,
>> 4 instances on 4 nodes, or any combination of up to 16 instances over 4
>> nodes. You just need to make sure that you have enough resources, that in
>> worst case, one node could run all instances.
>>
>> Regards
>> --------------------------------
>> Mike Epprecht, Microsoft SQL Server MVP
>> Zurich, Switzerland
>>
>> IM: mike@xxxxxxxxxxxx
>>
>> MVP Program: http://www.microsoft.com/mvp
>>
>> Blog: http://www.msmvps.com/epprecht/
>>
>> "Michael G via SQLMonster.com" <forum@xxxxxxxxxxxxxx> wrote in message
>> news:541CE6C54F90F@xxxxxxxxxxxxxxxxx
>>> Normally, clustering is setup as a 1-to-1 relationship between active
>>> and
>>> passive nodes, at least that is my understanding. We have a situation
>>> where
>>> we are being asked to setup a 2 active node, 1 passive node environment.
>>> Here's the question - if one of the active nodes fails, it fails over to
>>> the
>>> passive node. Now what happens if the 2nd active node fails? Will the
>>> other
>>> active node (originally the passive node) handle the failover or will it
>>> try
>>> to failover to the first active node that failed or will the whole thing
>>> just
>>> grind to a screeching halt? I know we can setup a 2 active/ 2passive
>>> node
>>> setup, but we wanted to research the 2-to-1 possibility as well.
>>>
>>> Thanks!
>>>
>>>
>>> --
>>> Message posted via http://www.sqlmonster.com
>>
>>
>
>


.

Relevant Pages

  • Re: Clustering with 2 active nodes and 1 passive node
    ... > You have an instance of SQL Server running on an node. ... > If you have 2 nodes, one sits around waiting for a failover. ... >> we are being asked to setup a 2 active node, 1 passive node environment. ...
    (microsoft.public.sqlserver.clustering)
  • SQL Server service on active/passive
    ... I have inherited 2 node active/passive SQL Server cluster. ... noticed that SQL Server service is running on active node only. ... In case of failover, will SQL Server ... it be replicated to passive node in case of failover. ...
    (microsoft.public.sqlserver.clustering)
  • Re: SQL Server service on active/passive
    ... > I have inherited 2 node active/passive SQL Server cluster. ... > noticed that SQL Server service is running on active node only. ... the node that runs the SQL instance is the active node. ... > In case of failover, will SQL Server service start automatically on ...
    (microsoft.public.sqlserver.clustering)
  • Conditions for Cluster to failover..
    ... Under what conditions will the active node fail to the passive node when ... Does it failover if the CPU on active node is pegged at 100%? ...
    (microsoft.public.sqlserver.clustering)
  • Re: Dear Ekrem
    ... I do not think you know the difference between Two Active Nodes in a Cluster or only one active node. ... When you have only one active node in your cluster, then you will be able to use only one SQL Server server at one time. ... So they said that they want to keep a live copy of their databases on the second node that's why they wanted two active nodes. ...
    (microsoft.public.sqlserver.setup)