For questions about database mirroring - a technology used to create and maintain an exact copy of a database, synchronously or asynchronously.

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13
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3answers
16k views

What can cause a mirroring session to timeout then failover? SQL Server 2005

We have two production SQL Servers running SQL Server 2005 SP4 with cumulative update 3. Both servers run on physical machines that are identical. DELL PowerEdge R815 with 4 x 12 core CPUs and 512GB ...
11
votes
2answers
3k views

Best way to migrate a huge SQL Server database with low downtime over network

Problem definition Our database server needs to be transferred to an other datacenter. It runs on Microsoft SQL Server 2012 Enterprise (64-bit) and contains two databases of about 2TB and 1TB. ...
10
votes
2answers
1k views

If I fail over one database, do the others that share the same mirror endpoint fail over as well?

We have two databases setup for mirroring on a single SQL Server instance: a test database and a production database. Both get mirrored to another server using the exact same endpoints. If I go into ...
10
votes
1answer
10k views

Mirroring - Server network address cannot be reached

I have SQL Server 2008 R2 Installed. It contains three instances. Default (MSSQLServer) First Instance Second Instance All these are Log On as Network Service.. Default Instance is Principal ...
9
votes
2answers
6k views

How to create an Event Notification that runs a Job/procedure when mirroring state changes

I'm asking this question in the sequence of this one Can I send a string over TCP using T-SQL? Remus Rusanu exposes what it seems to be an optimal solution for my problem, but... I'm too immature to ...
9
votes
1answer
258 views

Why my database mirror break down after changing file group settings from RESTRICTED_USER to MULTI_USER?

My environment is the following: VMWare 5.5 vitalized server MS Windows Server 2008R2 Enterprise domain and SQL Server 2008 R2 Enterprise. Centralized storage with fibre-channel connection. I have ...
8
votes
1answer
11k views

Breaking and Restoring a mirror

I have to do some maintenance on a secondary node of a mirror. Since this is the result of the site becoming slow while the mirror re-established after a brief network outage I want to be safe and ...
8
votes
2answers
11k views

What are the differences between Mirroring and Failover Clustering and when is each one recommended over the other?

What are the main differences between Mirroring and Failover Clustering? What kind of problem each one solves and in what kind of scenarios is each one recommended over the other?
8
votes
2answers
584 views

Mirroring the Distributor

Has anyone had success with mirroring the distribution database? We have a dedicated server as a Distributor. It handles all our push replication from prod to reporting. We'd like to build an ...
8
votes
2answers
710 views

Mirror log empty on primary but fine on the mirror

We have dozens of principle servers and corresponding mirrors, most are working fine, however, 1 of them is acting strange. Specifically, the sp_dbmmonitorresults proc returns all columns as NULL for ...
7
votes
1answer
4k views

Database Mirroring with TDE

I have the requirement of mirroring a few databases and also using transparent data encryption (TDE) on them as our data must be encrypted while 'at rest'. I have setup TDE on both the principal and ...
7
votes
2answers
6k views

Transaction Log maintenance on Mirror database

SQL Server Version: 2008 R2 Enterprise SP2 I am trying to get a handle on our SQL Server maintenance and I came across something I think is incorrect. We have a single production instance with 3 ...
7
votes
1answer
688 views

Alerting on Database Mirroring Events

I am looking for the actions one must take to cause Threshold Alerts to occur for a single mirrored database on an instance of SQL Server 2008 containing multiple mirrored databases. FYI: This is ...
7
votes
3answers
406 views

Should we periodically 'refresh' the mirrored copy of a SQL Server database?

When you have SQL Server mirroring set up, do you trust that your mirror database will stay the same as the primary, even after months and months of mirroring?  I know we all check the status, ...
7
votes
1answer
464 views

Enabling TDE without breaking existing mirror

I've been trying to enable TDE in a mirrored SQL Server 2008 R2 configuration. Enabling TDE is not so difficult, though when I enable TDE on the principal, the mirror database goes in to a suspended ...
6
votes
3answers
1k views

SQL Server 2008 mirrored Database with manual failover, need reporting database

Our current setup is a principal database used in production with a manual failover mirrored database for HA. I need to setup a reporting database as well. What would be the best approach? Shall I ...
6
votes
4answers
8k views

Reconnect mirroring server SQL2008 R2

The failover server has status (Mirror, Disconnected, In recovery) and principal server has status (Principal, Disconnected). What is the process to reconnect these servers?
6
votes
3answers
6k views

How can I inspect the security settings of a SQL Server Endpoint?

I am in the process of creating a TEST environment for our SQL Server development staff. In production we have 3 SQL Servers, SQL01 contains several databases that are mirrored to SQL02. SQL03 ...
6
votes
2answers
3k views

Transaction Log and mirroring - looking for dumbest explanation possible

First of all I must admit that I struggle with concept of Transaction Log. I mean - I do understand that it is Log of all Transactions that happen on database, but when it comes to properly putting it ...
6
votes
1answer
1k views

Mirroring problems after removing domain

I successfully created a mirror with certificates between two servers. One of those servers was a domain controller. After removing the domain the mirror was interrupted. After hours of searching I ...
6
votes
2answers
92 views

SQL Server Backup transaction error

Hi I am attempting to backup the transaction log file to setup mirroring in SQL Server I execute BACKUP LOG CUSTOMER TO DISK ='K:\JonDB\CUSTOMER.trn' WITH INIT GO And I receive Processed 6587361 ...
6
votes
1answer
8k views

Can I shrink the transaction log file on a mirror database?

This is a followup question to a previous question about why I couldn't shrink the log file on the principal database. To make a long story short, I setup database mirroring but forgot to make sure ...
6
votes
1answer
225 views

Should I pause mirroring when I reboot the witness server?

So I know that when patching the two main database servers (SQL Server for the record) you do the mirror, failover and then when it's all caught up do the new mirror, but what about the witness box? ...
6
votes
1answer
209 views

Retrieving cached plans fails due to cached objects of database Mirror

I'm trying to retrieve cached execution plans for a specific database object, but this fails because of cached plans which belong to a mirrored database in MIRROR state. The below query, without any ...
6
votes
2answers
3k views

Mirroring in SQL Server 2012

I've got newly installed Win 2008 R2 machines, in a workgroup, in the same subnet, and of course SQL Server 2012. I allowed login with SQL Server authentication, thinking it may help with each ...
6
votes
2answers
3k views

How do I shrink the physical Transaction Log file when it's the principal in a mirror?

We setup database mirroring over the weekend, and forgot to re-enable the job that backs up the transaction logs. When I came in this morning, the transaction log had ballooned to 58GB, and was taking ...
6
votes
1answer
187 views

Microsoft SQL Server 2012 Mirrors Go Into Disconnected

I have some Microsoft SQL server 2012 mirrors, without a witness in asynchronous mode, that are sporadically going into disconnected. I am running SQL Server 2012 11.0.5058. Looking at the logs on ...
5
votes
3answers
2k views

How to reduce network latency during mirroring?

We are using SQL Server 2008 R2 Standard edition for mirroring. But we found out that network latency is too high. It takes nearly four times time to complete a transaction while mirroring is active. ...
5
votes
2answers
2k views

SQL Server replication for off site copy

We have our Primary SQL Servers in-house (15 primary servers at the moment (500 databases approx overall), most of the servers have hex core processors). These are mirrored to other backup servers in ...
5
votes
2answers
3k views

Manually moving SQL instance to another node causes immediate database mirror failover

I have a two-node SQL cluster (2008 R2). Some of the databases within that SQL instance are mirrored to another server on a remote site, using the High safety with automatic failover. The mirroring ...
5
votes
1answer
213 views

SQL Server Mirroring kicks in before cluster has time to fail over

I have two clusters each with two nodes configured in active/passive; the two clusters take part in a high-availability mirroring session using a separate server as the witness. When a node fails in ...
5
votes
1answer
375 views

Should I use Database Mirroring?

So I have the following scenario on my hands: I have a product database that runs for a specific app, all inserts into the database come in through three separate connections. Recently I have ...
5
votes
1answer
2k views

Failover scenario with principal “hard down”

My company has a failover pair of SQL Server 2005 instances, which provide database availability for a UL-licensed alarm/call center, where uptime and availability are critical for life safety. ...
5
votes
3answers
1k views

Is there an easy way to trigger automatic failover of a single mirrored database?

I have 3 mirrored databases on a single instance of sqlserver2008-R2 in a high safety with automatic failover config. Is there a way to trigger automatic failover of just 1 database? I want to ...
5
votes
1answer
2k views

SQL Server ODBC Mirror/Failover Partner

Background/Context We are in the process of moving our SQL Server 2000 databases to a mirrored SQL Server 2008 R2 server with a witness and automatic failover. We have both .Net and Access ...
5
votes
1answer
571 views

Mirroring partner timeout - Not working the way advertised?

I'm testing a 2 node windows failover cluster with mirroring in high safety mode and automatic failover. My mirror is a standalone server as is the witness. All instances are 2008 R2 RTM Enterprise ...
5
votes
1answer
560 views

Changing autogrow settings with database mirroring

Recently I changed the Autogrow settings for some of the databases on our SQL Server 2008 R2 server. These are involved in a database mirroring configuration, with the principal on SERVER1 and the ...
4
votes
2answers
62 views

Quickest way to migrate mirroring to AG

Scenario is this, prod is two two node FCI with mirroring (primary/disaster DC). This is working just fine. New hardware is coming and a version upgrade to SQL Server 2012 (from 2008 R2) in the form ...
4
votes
5answers
2k views

Setting up a Redundant Sql Server 2008 Configuration While Retaining High Performance and Minimal Downtime

We have a situation where we are moving to a new hosting facility and are attempting to configure our new database environment. However, none of us are formal DBA's so a lot of what we are doing is ...
4
votes
3answers
3k views

How to sync the data between two identical DB

The thing is I've two identical databases, one is in my localhostserver at my laptop and the other one is on the office main server. Is there any automatic way or software that can synchronize the ...
4
votes
1answer
1k views

SQL Server 2008 R2 Readable Mirror

I know that SQL Server 2012 and 2014 offer AlwaysOn Availability Groups which provide this functionality, but I'm still stuck on SQL Server 2008 R2 for a while. I recently came across this AWS ...
4
votes
2answers
797 views

What happens in this strange SQL Server Mirroring situation?

Let's assume that two SQL Server instances (S1 and S2) are in synchronous mirroring or in a synchronous Availability Group. Now the following happens: A write happens on S1 and transaction commit is ...
4
votes
1answer
620 views

Impact of an Asynchronous Mirror / Full Recovery Model on Performance

For an asynchronous mirror in SQL Server 2008 R2, using the full recovery model is required. Assuming that the network and disk IO on both sides of the Mirror can keep up with the transaction logs ...
4
votes
1answer
290 views

AlwaysOn AG - CPU limitations

I’ve been trying to find out if the same CPU limitations database mirroring has apply to Availability Groups. My guess is that the same limitations exists, given that Availability Groups was built on ...
4
votes
2answers
3k views

Should I pause Mirroring and stop SQL Server services before running windows updates?

I am running Windows update on my SQL Servers (which are in a Principal-Mirror partnership, in High Safety mode). I am starting with updating the mirror and I was wondering, to increase safety, ...
4
votes
1answer
511 views

SQL Server DR, mirroring or virtualise and mirror

I have a client with a small business server 2008 Premium installation. This obviously includes SQL Server 2008 standard on a separate 2008 server. On the SQL we run several line of business ...
4
votes
1answer
2k views

Version of Witness Server for mirroring SQL 2012

Can I use SQL 2008 R2 as a Witness Server for 2 instances of SQL 2012 Servers being mirrored?
4
votes
1answer
228 views

What data gets passed between mirroring principal and secondary?

We are trying to figure out which of the below statements is correct when talking about SQL Server mirroring: The master database server executes the query, and takes the resulting transactions and ...
4
votes
3answers
387 views

Make a Copy of a Microsoft SQL Server 2005 database from a Mirror Copy

I have a SQL mirror database in Microsoft SQL Server 2005. I would like to get a copy of it as a new database so I have the ability to read, write, and backup the database. I cannot break the ...
4
votes
2answers
256 views

Impact of deleting 100GB table on Mirroring

I'm about to delete a large table which is approximately 100GB in size. I'd like to understand the impact on the mirroring that's in place on this db. Can anyone confirm?