Skip to main content
OverflowAI is here! AI power for your Stack Overflow for Teams knowledge community. Learn more

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

Filter by
Sorted by
Tagged with
0 votes
0 answers
36 views

Why do I get DAC error even though it is disabled?

I get the following error sometimes: Could not connect because the maximum number of '1' dedicated administrator connections already exists. Before a new connection can be made, the existing ...
variable's user avatar
  • 3,634
2 votes
1 answer
246 views

Azure SQL Database - dedicated administrator connection (DAC)

If you check the setting in any of your Azure SQL databases, you will see that the value_in_use column value is zero for Remote admin connections. Meaning ‘Remote admin connections’ are not allowed ...
SqlWorldWide's user avatar
  • 13.2k
0 votes
0 answers
64 views

DAC connection to sql instance not working [duplicate]

I have configured one remote sql server with 2 instances A,B. I have enabled TCP/IP,Port 1434, remote connections, sql browser running and firewall inbound rule. I've enable DAC using sp_configure '...
Elena2020's user avatar
0 votes
2 answers
355 views

SQL server DAC connection to mssqlsystemresource database

I have a problem while connecting to the mssqlsystemresource database. When I try to connect with DAC connection (without restarting SQL server with -m option) it works, but I can't use the ...
ARAZI's user avatar
  • 1
1 vote
1 answer
80 views

Why do I need DAC if I am able to connect to the server via sqlcmd?

DAC attracted my attention at the moment when I was unable to connect to the SQL Server using a traditional way (the reason was deleting logon trigger). I made some searches on the web and it turned ...
Rauf Asadov's user avatar
  • 1,273
1 vote
0 answers
141 views

How many connections does Object Explorer use in SSMS?

I recently enabled DAC and noticed this error when first trying to connect with object explorer in SSMS: Cannot connect to admin:servername Dedicated administrator connections are not ...
Ross's user avatar
  • 91
2 votes
0 answers
36 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 ...
Peter Vandivier's user avatar
0 votes
0 answers
230 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 ...
DBA_Kyle's user avatar
5 votes
2 answers
3k views

"the maximum number of '1' dedicated administrator connections already exists" message in error log when connecting to DAC from Powershell

I'm connecting to SQL Server (2016 and 2017 latest builds) via the Dedicated Administrator Connection (DAC) from PowerShell. The following error message is recorded in the SQL Server Error Log: Date ...
RelativitySQL's user avatar
3 votes
2 answers
757 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 ...
VitalicJJ's user avatar
5 votes
1 answer
1k 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 ...
Gavin Harris's user avatar
3 votes
1 answer
2k 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?
Santhoshkumar KB's user avatar
6 votes
2 answers
3k 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, ...
Racer SQL's user avatar
  • 7,386
3 votes
1 answer
809 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....
Evan Carroll's user avatar
  • 63.4k
1 vote
1 answer
12k 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,...
Evan Carroll's user avatar
  • 63.4k
1 vote
1 answer
668 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 ...
Evan Carroll's user avatar
  • 63.4k
4 votes
1 answer
992 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 ...
Evan Carroll's user avatar
  • 63.4k
2 votes
2 answers
1k 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 ...
user3601171's user avatar
0 votes
3 answers
2k 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 ...
Magier's user avatar
  • 4,787
4 votes
1 answer
197 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 ...
Md Haidar Ali Khan's user avatar
2 votes
2 answers
3k 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 ...
user3469285's user avatar
2 votes
0 answers
866 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 ...
CJ Gregory's user avatar
16 votes
3 answers
12k 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 ...
user avatar
2 votes
1 answer
10k 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 ...
ivanmp's user avatar
  • 2,323