Questions tagged [dac]

Dedicated Admin Console (DAC) a reserved connection on SQL Server that grants special access to system tables and can help diagnose problems

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votes
3answers
8k views

Is it possible to estabilish Dedicated Administrator Connection (DAC) using SSMS?

Is it possible to connect to the DAC using SSMS? If I understand correctly, it should be possible by using "admin:" prefix before the server name, but I receive the following message: Dedicated ...
5
votes
2answers
372 views

Enabling admin connection on SQL Server Express to fix logon trigger

Well, luckily I got this error on my test environment. I'm so scared about this error that I disabled all logon triggers I was using on production environment. I created the famous logon trigger, ...
4
votes
1answer
312 views

Static DAC ports for named instances

Using SQL 2016 Enterprise Edition The default instance will listen on 1433 and the DAC port will listen on TCP 1434. SQL Browser will listen on UDP 1434. Any subsequent named instances will get a ...
4
votes
1answer
131 views

Is it possible to connect MS SQL Server Express 2012 through DAC Connection?

Is it possible to Connect MS SQL Server 2012 Express Through DAC. After moving from SQL Server 2012 Enterprise to MS SQL Server 2012 Express, some performance problem were there. When i have checked ...
3
votes
1answer
1k views

How do we find who used Dedicated Admin Connection

Is there any way to find who used Dedicated Admin Connection? Not active connection but the previous one which is already closed?
3
votes
1answer
284 views

How do I know what requires DAC?

Playing around with SQL Server, I came across a semi-cryptic error. Essentially, I only need to log into DAC. Is there any general advice for when DAC is needed? How do I know I need it to access sys....
3
votes
1answer
506 views

How do I log into the Dedicated Admin Console (DAC) on Linux?

sqlcmd is documented to have, Login-Related Options -A Logs in to SQL Server with a Dedicated Administrator Connection (DAC). This kind of connection is used to troubleshoot a server. This ...
3
votes
2answers
229 views

Why SQL Server Service Account connects to the DAC?

We started getting Alerts: Could not connect because the maximum number of '1' dedicated administrator connections already exists. Before a new connection can be made, the existing dedicated ...
3
votes
0answers
114 views

When using DAC, receiving the “[…] the maximum number of '1' dedicated administrator connections already exists” message in error log

I am about to escalate this to MS, but I thought I would try here first and see if anyone has any ideas as to how to prevent this faux error message... When connecting to SQL Server (2016 and 2017 ...
2
votes
1answer
8k views

Clients timing out with no apparent reason

I have a SQL Server 2005 server that's been running fine most of the time. Today the users started to get time outs when opening new connections, including myself when I tried to open another tab on ...
2
votes
2answers
2k views

DAC connection error

I'm having a problem connecting using my dedicated admin connection in SQL Server 2014. I just wanted to test it out. I have DAC enabled in sp_configure. I have performed RECONFIGURE. I have ...
2
votes
0answers
24 views

DAC silently swallows tokenization errors in sp_msforeachdb

This morning I hopped on the DAC to check something out. Oops, I made a typo! 1> exec sp_msforeachdb N' 2~ use [?] 3~ select N'?', count(*) from sys.sysrscols; 4~ ' 5> go 1> Can you spot ...
2
votes
0answers
618 views

Severity 20 Error upon disconnecting Dedicated Administrator Connection

Starting working with Dedicated Administrator Connections on SQL Server 2008 R2 servers. All is working fine (once port 1434 was opened), but am getting severity 20 errors when I disconnect the admin ...
1
vote
1answer
195 views

SQL Server Error “Database 'mssqlsystemresource' does not exist.”

On Linux, whenever I run use mssqlsystemresource to get access to Resource Database, I get an error. How do I resolve this. 1> use mssqlsystemresource 2> go Msg 911, Level 16, State 1, Server ...
1
vote
1answer
336 views

SQL Server Management Studio DAC connection error

I'm trying to connect to SQL Server 2012 via DAC using Management Studio. I type admin: before my server name, yet I keep getting the same error: A network-related or instance-specific error ...
0
votes
3answers
749 views

No DAC connection could be established on the default port. Make sure DAC is enabled

I could not establish a local DAC connection using SSMS while I was logged into the Sql-Server's Operating System's Remote Desktop. First reason was SQL-Browser Service turned off. Lateron, second ...
0
votes
1answer
4k views

Why am I getting “Invalid object name 'sys.sysobjvalues'.” [duplicate]

When I run SELECT OBJECT_DEFINITION(OBJECT_ID('sys.assembly_files')); I can see that there is a self-join on sys.sysobjvalues, but when I try to select that table I get, Msg 208, Level 16, State 1,...
0
votes
0answers
31 views

SQL Server DAC - Connection Issue

I am having a strange issue when trying to connect to my SQL Server instance remotely from my client computer. I am able to do this on my other instances by opening up a new Database Engine Query and ...