INFORMATICS

Make sure you have full backups of your databases.

On the primary replica node, change the failover mode to manual

Refresh the databases and check if MSSQL reports any errors

Apply fix - CU0x service pack Perform an update for all databases until all fixes are uploaded.

After uploading patches and restarting MSSQL, check if the cluster is in good condition. P

erform an update for the Primary server.

After uploading all patches, check if the cluster is in good condition.

If there are no errors, change the switching mode from manual to automatic.

Apply SQL Server patches or cumulative updates in SQL Server Always On Availability Groups (sqlshack.com)

SQL SERVER - How to Apply Patch in AlwaysOn Availability Group Configuration? - SQL Authority with Pinal Dave

After the server failure, I lost access to the database copies and to the configured agents. How to recreate agents jobs.

Within the MSDB database, jobs are stored in a tables called dbo.sysjobs. This joins to a table called dbo.sysjobsteps that stores details of the individule steps. The schedules are stored in dbo.sysjobschedules and the History is stored in dbo.sysjobhistory.

MSDB will also contain other instance level objects such as alerts, operators and SSIS packages.

A script that shows us where and how SQL Server stores SQL jobs.

-- List of all the SQL Jobs on a server with steps
SELECT
     job.job_id,
     notify_level_email,
     name,
     enabled,
     description,
     step_name,
     command,
     server,
     database_name
FROM
    msdb.dbo.sysjobs job
INNER JOIN 
    msdb.dbo.sysjobsteps steps        
ON
    job.job_id = steps.job_id
WHERE 1=1
    --AND job.enabled = 1 -- uncomment this to see enabled SQL Jobs



and next example also gets the category name and filters out the report server jobs.

SELECT  sysjobs.name 'Job Name',
        syscategories.name 'Category',
        CASE [description]
          WHEN 'No Description available.' THEN ''
          ELSE [description]
        END AS 'Description'
FROM    msdb.dbo.sysjobs
        INNER JOIN msdb.dbo.syscategories ON msdb.dbo.sysjobs.category_id = msdb.dbo.syscategories.category_id
WHERE   syscategories.name <> 'Report Server'
ORDER BY sysjobs.name 

Jobs are stored in the msdb database. You will have to restore this.

After the server failure, I lost access to the database copies and to the configured agents. How to recreate agents jobs.

Within the MSDB database, jobs are stored in a tables called dbo.sysjobs. This joins to a table called dbo.sysjobsteps that stores details of the individule steps. The schedules are stored in dbo.sysjobschedules and the History is stored in dbo.sysjobhistory.

MSDB will also contain other instance level objects such as alerts, operators and SSIS packages.

A script that shows us where and how SQL Server stores SQL jobs.

-- List of all the SQL Jobs on a server with steps
SELECT
     job.job_id,
     notify_level_email,
     name,
     enabled,
     description,
     step_name,
     command,
     server,
     database_name
FROM
    msdb.dbo.sysjobs job
INNER JOIN 
    msdb.dbo.sysjobsteps steps        
ON
    job.job_id = steps.job_id
WHERE 1=1
    --AND job.enabled = 1 -- uncomment this to see enabled SQL Jobs



and next example also gets the category name and filters out the report server jobs.

SELECT  sysjobs.name 'Job Name',
        syscategories.name 'Category',
        CASE [description]
          WHEN 'No Description available.' THEN ''
          ELSE [description]
        END AS 'Description'
FROM    msdb.dbo.sysjobs
        INNER JOIN msdb.dbo.syscategories ON msdb.dbo.sysjobs.category_id = msdb.dbo.syscategories.category_id
WHERE   syscategories.name <> 'Report Server'
ORDER BY sysjobs.name