These technologies usually create there own cmdlets, and then bundle into a "Module" for distribution.
SQL team initially followed different approach by creating mini-shell "sqlps.exe" but it was not well accepted.
Now, they give there cmdlets in SQLPS module.
"Import-Module SQLPS" command loads this module.
There are multiple cmdlets available for multiple tasks like querying, backup/restore, security management, policy management etc. . Two cmdlets for taking backup/restore are :
These two use SMO(Server Management Objects) classes underneath and then run T-SQL commands.
Backup-SqlDatabase is a wrapper over SMO object model (managed code); SMO constructs T-SQL code and executes query using ADO.NET.
SMO classes have been available for a long time, and are widely used in automation.
There are different ways to perform backup/restore operations as specified here.
However, both these have one serious bug i.e. if a backup or restore takes more than 10 minutes, they time-out and fail.
Usually, backup/restore of large databases take more than 10 minutes to complete (which is why we wanted to automate this).
Here's the error you will see if you run this command :
Backup-SqlDatabase -ServerInstance $Server -Database $DatabaseName -BackupFile $BackUpFile -CompressionOption On -ConnectionTimeout 0 -Initialize -Verbose -ea Stop
Here’s the error exactly after 600 seconds of execution :
VERBOSE: 60 percent processed.
VERBOSE: The backup or restore was aborted.
The wait operation timed out
+ CategoryInfo : InvalidOperation: (:) [Backup-SqlDatabase], Win3
+ FullyQualifiedErrorId : ExecutionFailed,Microsoft.SqlServer.Management.P
+ PSComputerName : localhost
This is a very weird issue.
You can try re configuring “remote query timeout” to 0 as given here, but the issue persists.
ConnectionTimeout switch is different than StatementTimeout. This switch is not available in these cmdlets.
The workaround lies in setting this property by connecting to SMO server.
$serverConn = New-Object ("Microsoft.SqlServer.Management.Smo.Server") $server
$serverConn.ConnectionContext.StatementTimeout = 0
So, I have to pass SMO.Server object to this cmdlet.
Backup-SqlDatabase -InputObject $serverConn -Database abc -BackupFile "L:\123\abc.bak"
This will run fine for command that take longer than 600 seconds.( Default value of StatementTimeout is 600, which caused the issue).
To tell Microsoft about this, I've logged a bug in their "Connect" program.
PS: If Power Shell is giving you some issues, don't worry. Invest time in learning and sharing. Overall, your time will be saved.
Tip : I came around this workaround after using the best cmdlets of Power Shell : Get-Help, Get-Member.
These are your base including Get-Command.