SQL Server database restore – preparations and tests that we must perform before starting the restore

Goal

To obtain information about the target database files , to check the backup file that we have to use, to estimate the space required and to have a list with steps done and a list with steps to do

My way of achieving it

Using linked server and xp_cmdshell. The restore operation of a SQL Server database is something that requires most of the time careful attention especially when it comes to big databases when the restore operations is time consuming and we would like to have all in place before the restore. Not only that requires our full attention, the restore requires also preparation which is in many cases time consuming and prone to errors and mistakes or something that usually I forget to check. Because of this I decided to create a script that will check some of the things required for a potentially successful restore. The script performs the following verifications:
– checks if the bak file is accessible from the target instance
– checks the drive information of the target instance for space available for the restore
– checks if target instance is older than source instance since backups from newer versions of SQL cannot be restored on old versions
– checks the full bak file for information about the size of the files that will be restored
– check if target database exists on target instance
– check if we have space for individual database files restores and if not provides some alternative locations for relocation
– generate the restore command, is very basic one that needs to be changed in case target database doesn’t exist on target instance

Before using the script we must modify the @sourceinstance, @targetinstance, @sourcedb and @targetdb with the right information.

Th output of the script is below

restoreprerequistes

The script can be downloaded from here

Display group membership (including nested groups) of a domain account using SQL Server

Goal

To obtain a list of groups that a domain account is member of.

My way of achieving it

Using SSMS and Ad Hoc Distributed Queries. In order to use AD Hoc Distributed queries temporary you must enable it using sp_configure.

Sometimes when we need to troubleshoot why a domain account doesn’t have the requested permissions we have to check his group membership. Most of the time the access to SQL server is given by making an user member of a specific active directory domain group and have that group added as a login or by adding that domain account as a login. Although most of the time this action will solve the request there might be cases when the users say that they don’t have the same rights as other users. This post address this situation by discovering the group membership of those domain accounts. Although we can use net user command with domain switch in a command prompt window

– net user domain_account /domain

the problem is that this will not return any nested groups.

When comparing 2 domain accounts for differences that they might have in SQL Server in regards to permissions we want to be sure that those accounts have the same group membership.

The output of the script is below and can be downloaded from here

groupmembership

 

SQL Server cluster – checking if SQL Server clustered instance is running on preferred node

Goal

Obtaining information about the SQL Server clustered instances and if they are running on the preferred node

My way of achieving it

Using SSMS, xp_cmdshell and WMIC. When we have to check and see if our clustered instances are running on the preferred node we can use different approaches and each approach has its own benefits in comparison with the other approaches. In my case because I am used to work more with SQL Server, the usage of SSMS, xp_cmdshell and WMIC is more appealing than everything else and I chose it to find that information.

The script is using:

– 1 WMIC query that uses MSCluster_ResourceGroupToResource – used to find all the groups that are related to SQL Server clustered instances

– 1 WMIC query that uses MSCluster_ResourceGroupToPreferredNode – used to find the preferred node for all the groups

The output returned by the first query is used to generate a result set of group names and the name of the SQL Server clustered instance that is found in each group.

GroupName  InstanceName
SQL11 SQL11\I11

The output above is used to actually generate the script that we will have to ran in SSMS after enabling the SQLCMD mode. Below is an example of the generated script.

:CONNECT APPDKBA1162

DECLARE @preferrednodes TABLE (line nvarchar(500))
DECLARE @InstanceInformation TABLE (InstanceName nvarchar(100), RunsON nvarchar(50), IsPreferredNode nvarchar(3), Comments nvarchar(max))
DECLARE @groupsandinstance TABLE (GroupName nvarchar(500), InstanceName nvarchar(100))
DECLARE @GroupName nvarchar(50)

BEGIN TRY

INSERT INTO @groupsandinstance VALUES (‘SQL Server (MSSQLSERVER)’,’APPDKBA1162′)
INSERT INTO @groupsandinstance VALUES (‘SQL11′,’SQL11\I11’)

SELECT @GroupName = GroupName FROM @groupsandinstance WHERE InstanceName = @@SERVERNAME
INSERT INTO @preferrednodes EXEC xp_cmdshell ‘wmic /namespace:\\root\mscluster path MSCluster_ResourceGroupToPreferredNode’
UPDATE @preferrednodes SET line = REPLACE(line,CHAR(13),”)

IF (SELECT COUNT(line) FROM @preferrednodes WHERE line like ‘%.Name%’ AND line like ‘%’+@GroupName+’%’) > 1
INSERT INTO @InstanceInformation
SELECT CONVERT(nvarchar(50),@@SERVERNAME) AS InstanceName, CONVERT(nvarchar(50),SERVERPROPERTY(‘ComputerNamePhysicalNetBIOS’)),
(SELECT TOP 1 CASE WHEN CHARINDEX(CONVERT(nvarchar(100),SERVERPROPERTY(‘ComputerNamePhysicalNetBIOS’)), line) > 0 THEN ‘YES’ else ‘NO’ END FROM @preferrednodes WHERE line like ‘%.Name%’ AND line like ‘%’+@GroupName+’%’ ),”
ELSE
INSERT INTO @InstanceInformation
SELECT CONVERT(nvarchar(50),@@SERVERNAME) AS InstanceName, CONVERT(nvarchar(50),SERVERPROPERTY(‘ComputerNamePhysicalNetBIOS’)),
(SELECT CASE WHEN CHARINDEX(CONVERT(nvarchar(100),SERVERPROPERTY(‘ComputerNamePhysicalNetBIOS’)), line) > 0 THEN ‘YES’ else ‘NO’ END FROM @preferrednodes WHERE line like ‘%.Name%’ AND line like ‘%’+@GroupName+’%’ ),”

SELECT * FROM @InstanceInformation

END TRY
BEGIN CATCH
INSERT INTO @InstanceInformation SELECT CONVERT(nvarchar(50),@@SERVERNAME) AS InstanceName, CONVERT(nvarchar(50),SERVERPROPERTY(‘ComputerNamePhysicalNetBIOS’)) AS RunsON,” AS IsPreferredNode,(select ERROR_MESSAGE()) AS Comments
SELECT * FROM @InstanceInformation
END CATCH

GO

:CONNECT SQL11\I11

……….

Below you can see the output of the script

iropn_1

The script can be downloaded from here

SQL Server troubleshooting – what happened with my database

Goal

Obtaining in the same SSMS window, information about why a database might have been unavailable or having its status changed.

My way of achieving it

Almost all of the monitoring deployed solutions these days raise tickets every time a database becomes unavailable and from the DBA operational point of view this means that we must connect and check what happened with the database and take the required actions. Of course that depending of the monitoring implementation some tickets will be closed automatically if during the second check the database becomes online but this doesn’t mean that we don’t need to try to see why the database status changed. Although we can do our investigation using GUI tools that SQL Server provides this approach has some limitations that the script used here tries to overcome. Below are some of the limitations:

– the account we use to connect to the server where SQL Server instance is running might not have rights to access the location where default trace files are stored which will make almost impossible the usage of SQL Server Profiler

– filtering or searching of SQL Server Error log files using SQL Server Log File Viewer was not designed to search or filter after multiple strings in the same time which makes the filtering or searching of the logs after string a and after string b impossible.

Because of this and other limitations I turned my attention and I tried to find other ways of searching and filtering SQL Server Error Log files and default trace and display the required information in only one window.

The output of the script in some cases will provide us enough information to see what happened while in other cases might give us only the name of the logins that were performing activities during that time.

dbstatus

The main benefit of this approach is that we can have in one window the information pertaining to that database from SQL Server Error log files and the default trace.

The script can be downloaded from here

SQL Server troubleshooting using performance counters

Goal

Sometimes when I need to troubleshoot one local or remote SQL Server instance I need to have information from inside SQL Server instance but also information outside of  it in order to start my investigation or take some conclusions. Most of the time this is a very time consuming operation and not always straight forward hence I the need to have something that I can re-utilize over and over again in these situations.

My way of achieving it

After searching and seeing what other people are doing when it comes to this I decided that I can combine some of the ideas found and put my own ideas in one script that I can use to have access to performance counters outside of  SQL Server but obtainable from SQL Server. I already mentioned in another post and I would like to mention it again that every script that I will post might have flaws or shortcomings and should be perceived as such. More than that the scripts can be considered the result of collective effort of different people  from the internet since I am taking and using what they were sharing over the internet.

The output of the script provides this type of information but the script can be modified to return the kind of information that you would like to have and use.  For me is important when troubleshooting a SQL Server instance to know:

– the processor utilization

– available memory

– disk utilization for the drives where sql server has files

– network utilization

Counter    Value
“\\WIN-666BDQE0KVL\Memory\Commit Limit”    4292546560
“\\WIN-666BDQE0KVL\Memory\Available MBytes”    1511
“\\WIN-666BDQE0KVL\Network Interface(Intel[R] PRO_1000 MT Network Connection)\Output Queue Length”    0
“\\WIN-666BDQE0KVL\Network Interface(isatap.{F5634C4F-D7A9-4921-924B-C112B6BC5377})\Output Queue Length”    0
“\\WIN-666BDQE0KVL\Network Interface(Local Area Connection* 11)\Output Queue Length”    0
“\\WIN-666BDQE0KVL\Network Interface(Intel[R] PRO_1000 MT Network Connection)\Bytes Total/sec”    0
“\\WIN-666BDQE0KVL\Network Interface(isatap.{F5634C4F-D7A9-4921-924B-C112B6BC5377})\Bytes Total/sec”    0
“\\WIN-666BDQE0KVL\Network Interface(Local Area Connection* 11)\Bytes Total/sec”    0
“\\WIN-666BDQE0KVL\Processor(_Total)\% User Time”    -1
“\\WIN-666BDQE0KVL\Processor(_Total)\% Privileged Time”    0
“\\WIN-666BDQE0KVL\Processor(_Total)\% Processor Time”    0
“\\WIN-666BDQE0KVL\LogicalDisk(C:)\Current Disk Queue Length”    0
“\\WIN-666BDQE0KVL\LogicalDisk(G:)\Current Disk Queue Length”    0
“\\WIN-666BDQE0KVL\Process(_Total)\Page File Bytes”    2915581952
“\\WIN-666BDQE0KVL\Process(sqlservr#3)\Page File Bytes”    434040832
“\\WIN-666BDQE0KVL\Process(sqlservr#3)\% User Time”    0
“\\WIN-666BDQE0KVL\Process(sqlservr#3)\% Privileged Time”    0
“\\WIN-666BDQE0KVL\Process(sqlservr#3)\% Processor Time”    0

typeperf

I will not explain here how the above output should be used since the goal of the post was only to provide a method to obtain performance counters outside of  SQL Server

The script can be downloaded from here

Interpreting sp_WhoIsActive stored procedure output for beginers

I will start my first post by apologizing in advance for any mistakes that most probably I will do but I hope that I will learn and educate myself on the way.

The idea behind this post came to me after I first heard about the stored procedure that Adam Machanic wrote and after I saw how useful was when troubleshooting or seeing what is happening to the SQL Server. Because depending on our role in the company and our day to day activities,  I realized that I need to have something that will refresh the meaning of the output till this output will become a second nature for me.  This was my attempt to take some of the information that he already made available in his blog ( http://sqlblog.com/blogs/adam_machanic/archive/2011/04/01/a-month-of-monitoring-part-1-of-30-a-brief-history-of-monitoring.aspx ) and put them in a format that in the beginning was easier for me to understand and communicate it to other colleagues. As with everything that I will post here this was my attempt and of course it has some flaws, some shortcomings but overall I believe it makes some sense for someone that is learning the output of this stored procedure and how to use it in the beginning. In order to use it we have to follow these steps

1. Create the stored procedure using the latest version of the SP from here http://sqlblog.com/files/default.aspx

2. Create a powershell script using the code provided at the end of this post.

3. Run the stored procedure with the parameters that you want but using this output column list. This is a prerequisite because the last columns depending on the parameters received by the SP will contain more than one line and the script cannot parse it correctly. We want to have those columns at the end in order to select all the columns expect those ones.

exec sp_whoisactive
@output_column_list = ‘[session_id][dd hh:mm:ss.mss][dd hh:mm:ss.mss (avg)][physical_io][reads][physical_reads][writes][tempdb_allocations][tempdb_current][CPU][context_switches][used_memory]
[physical_io_delta][reads_delta][physical_reads_delta][writes_delta][tempdb_allocations_delta][tempdb_current_delta][CPU_delta][context_switches_delta][used_memory_delta][tasks]
[status][wait_info][locks][tran_start_time][tran_log_writes][open_tran_count][blocking_session_id][blocked_session_count][percent_complete][host_name][login_name][database_name]
[program_name]start_time][login_time][request_id][collection_time][additional_info][sql_text][sql_command]’

4. Run the powershell script but not using the ISE. We will be prompted to select the command that you ran in SSMS and press enter after you made it available in the clipboard

PS C:\Users\Administrator\Downloads> .\sp_whoisactive10august2015.ps1
Select the command that you ran in SSMS and copy it in order to be available in the clipboard (Ctrl+C).
Press Enter to continue …:

5. After pressing enter we will have to provide the output of the command  by providing also the column names. Usually I am selecting only one row and all the column headers except the additional_info, sql_text and sql_command since these as we mentioned before, sometimes, have more lines and are not parsed right by the script

6. After pressing enter again the output is parsed and it provides more information about the columns and what those means

Below is a picture with step 4, 5 and 6 and because the script is not displaying the query the first line seems to be out of context since we are not pasting the query that is captured in the columns (sql_text or sql_command).

sp_whoisactive

The script can be downloaded from here