Billy Pang
tuxedo_man at hotmail.com
Thu Sep 15 13:23:22 CDT 2005
thanks. it looks like in a three server quorum I need three copies of sql server. At the very minimum, it can be two standard editions (for the two partner servers) and one msde (for the witness server). Billy >From: Jim Lawrence <accessd at shaw.ca> >Reply-To: dba-sqlserver at databaseadvisors.com >To: dba-sqlserver at databaseadvisors.com >Subject: Re: [dba-SQLServer] sql server 2005 database mirroring - howmany >copies of sql server? >Date: Thu, 15 Sep 2005 05:31:12 -0700 > >Hi Billy: > >Very interesting. From your comments I checked out >http://www.microsoft.com/technet/prodtechnol/sql/2005/dbmirror.mspx You are >right in that the article(s) does not clearly state whether one or two >copies of the product are necessary. > >Jim > > >-----Original Message----- >From: dba-sqlserver-bounces at databaseadvisors.com >[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of Billy Pang >Sent: Wednesday, September 14, 2005 11:54 PM >To: dba-sqlserver at databaseadvisors.com >Subject: Re: [dba-SQLServer] sql server 2005 database mirroring - howmany >copies of sql server? > >Hi Jim: > >Not sure if it is publishing or subscribing in this scenario. Are you >talking about (snapshot) replication? > >Database mirroring is new in sql server 2005, which is a bit different than >replication. in database mirroring, there is a principal database, which >is > >what client accesses. if the principal database is disconnected, the >witness > >tells the mirror server to become the principal server; the failover is >automatic and transparent to the client; replication is like database >mirroring because there are two copies of the db except that in db >mirroring, the client only sees one database. replication probably good for >WANs; for db mirroring, it is preferred that all servers are on same domain >over standard network infrastructre. > >Billy > > > >From: Jim Lawrence <accessd at shaw.ca> > >Reply-To: dba-sqlserver at databaseadvisors.com > >To: dba-sqlserver at databaseadvisors.com > >Subject: Re: [dba-SQLServer] sql server 2005 database mirroring - > >howmany copies of sql server? > >Date: Wed, 14 Sep 2005 22:19:35 -0700 > > > >Hi Billy: > > > >Do you mean Publishing and Subscribing? I have setup two versions of SQL > >server (2000 Enterprise and 2000 Development) on a couple of computers >and > >have tested them passing data back and forth... It is quick process, > >something like Access synchronizing but at this time it is no more than a > >local backup. > > > >Jim > > > >-----Original Message----- > >From: dba-sqlserver-bounces at databaseadvisors.com > >[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of Billy >Pang > >Sent: Wednesday, September 14, 2005 7:58 PM > >To: dba-SQLServer at databaseadvisors.com > >Subject: [dba-SQLServer] sql server 2005 database mirroring - how many > >copies of sql server? > > > >Hello: > > > >I need someone to clarify database mirroring for me. How many copies of > >sql > > > >server do I need to configure a database mirroring session involving >three > >separate servers (that includes a witness server)? > > > >The scenario is this: in the quorum, there are three servers: the >principal > >server, the mirror server and the witness server. the principal server >has > >the original db; the mirror server has a copy of the db on principal > >server; > > > >the witness server watches both the principal server and the mirror >server. > > > >If the principal server goes down, the witness automatically tells the > >mirror server to take over as principal server, a process that takes 3 > >seconds. > > > >To establish the mirror session for all three servers, according MS > >eLearning course 2938, I perform the following: > > > >For the principal server's participation in the quorum: > >1) from the principal server, I run the alter database statement on the > >original db > > > >For the mirror server's participation in the quorum: > >2) from the mirror server, I run the alter database statement on the >mirror > >db > > > >For the witness server's participation in the quorum: > >3) from the PRINCIPAL server, I run the alter database statement on the > >original db > > > >Given step 3), I can't tell if I need 2 or 3 copies of sql server (ie. do >I > >need a copy of sql server on the witness server?) Am I missing something > >here? > > > >Thanks in advance, > >Billy > > > > > >_______________________________________________ > >dba-SQLServer mailing list > >dba-SQLServer at databaseadvisors.com > >http://databaseadvisors.com/mailman/listinfo/dba-sqlserver > >http://www.databaseadvisors.com > > > >_______________________________________________ > >dba-SQLServer mailing list > >dba-SQLServer at databaseadvisors.com > >http://databaseadvisors.com/mailman/listinfo/dba-sqlserver > >http://www.databaseadvisors.com > > > > >_______________________________________________ >dba-SQLServer mailing list >dba-SQLServer at databaseadvisors.com >http://databaseadvisors.com/mailman/listinfo/dba-sqlserver >http://www.databaseadvisors.com > >_______________________________________________ >dba-SQLServer mailing list >dba-SQLServer at databaseadvisors.com >http://databaseadvisors.com/mailman/listinfo/dba-sqlserver >http://www.databaseadvisors.com >