functions/Restore-DbaDbSnapshot.ps1
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#ValidationTags#FlowControl# function Restore-DbaDbSnapshot { <# .SYNOPSIS Restores databases from snapshots .DESCRIPTION Restores the database from the snapshot, discarding every modification made to the database NB: Restoring to a snapshot will result in every other snapshot of the same database to be dropped It also fixes some long-standing bugs in SQL Server when restoring from snapshots .PARAMETER SqlInstance The SQL Server that you're connecting to .PARAMETER SqlCredential Credential object used to connect to the SQL Server as a different user .PARAMETER Database Restores from the last snapshot databases with this names only. You can pass either Databases or Snapshots .PARAMETER ExcludeDatabase The database(s) to exclude - this list is auto-populated from the server .PARAMETER Snapshot Restores databases from snapshots with this names only. You can pass either Databases or Snapshots .PARAMETER Force If restoring from a snapshot involves dropping any other shapshot, you need to explicitly use -Force to let this command delete the ones not involved in the restore process. Also, -Force will forcibly kill all running queries that prevent the restore process. .PARAMETER WhatIf Shows what would happen if the command were to run .PARAMETER Confirm Prompts for confirmation of every step. .PARAMETER EnableException By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message. This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting. Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch. .NOTES Tags: DisasterRecovery, Snapshot, Backup, Restore, Database Author: niphlod Website: https://dbatools.io Copyright: (C) Chrissy LeMaire, clemaire@gmail.com License: MIT https://opensource.org/licenses/MIT .LINK https://dbatools.io/Restore-DbaDbSnapshot .EXAMPLE Restore-DbaDbSnapshot -SqlInstance sqlserver2014a -Database HR, Accounting Restores HR and Accounting databases using the latest snapshot available .EXAMPLE Restore-DbaDbSnapshot -SqlInstance sqlserver2014a -Database HR -Force Restores HR database from latest snapshot and kills any active connections in the database on sqlserver2014a. .EXAMPLE Restore-DbaDbSnapshot -SqlInstance sqlserver2014a -Snapshot HR_snap_20161201, Accounting_snap_20161101 Restores databases from snapshots named HR_snap_20161201 and Accounting_snap_20161101 #> [CmdletBinding(SupportsShouldProcess = $true)] param ( [parameter(Mandatory = $true, ValueFromPipeline = $true)] [Alias("ServerInstance", "SqlServer")] [DbaInstance[]]$SqlInstance, [Alias("Credential")] [PSCredential]$SqlCredential, [Alias("Databases")] [object[]]$Database, [object[]]$ExcludeDatabase, [object[]]$Snapshot, [switch]$Force, [Alias('Silent')] [switch]$EnableException ) process { if (!$Snapshot -and !$Database -and !$ExcludeDatabase) { Stop-Function -Message "You must specify either -Snapshot (to restore from) or -Database/-ExcludeDatabase (to restore to)" } foreach ($instance in $SqlInstance) { Write-Message -Level Verbose -Message "Connecting to $instance" try { $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential } catch { Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue } #$allDbs = $server.Databases $alldbq = @" SELECT sn.name AS Name, dt.name AS DatabaseSnapshotBaseName, sn.create_date AS CreateDate, CASE WHEN sn.source_database_id IS NOT NULL THEN CASE WHEN dt.state = 6 THEN 0 ELSE 1 END ELSE CASE WHEN sn.state = 6 THEN 0 ELSE 1 END END AS IsAccessible, CASE WHEN sn.source_database_id IS NOT NULL THEN 1 ELSE 0 END AS IsDatabaseSnapshot FROM sys.databases sn LEFT JOIN sys.databases dt ON sn.source_database_id = dt.database_id "@ $alldbs = $server.Query($alldbq) # vault to hold all programmed operations from --> to $operations = @() if (!$Snapshot -and !$Database -and !$ExcludeDatabase) { # Restore all databases from the latest snapshot Write-Message -Level Verbose -Message "Selected all databases" $dbs = $allDbs | Where-Object IsDatabaseSnapshot -EQ $true } elseif ($Database) { # Restore only these databases from their latest snapshot <# Note, for some reason lookup of this property has to be done using $_.DatabaseSnapshotBaseName Removing this will cause: Where-Object : A positional parameter cannot be found that accepts argument 'System.Object[]' #> Write-Message -Level Verbose -Message "Selected only databases" $dbs = $allDbs | Where-Object {$Database -contains $_.DatabaseSnapshotBaseName} } elseif ($ExcludeDatabase) { Write-Message -Level Verbose -Message "Excluded only databases" $dbs = $allDbs | Where-Object {$ExcludeDatabase -NotContains $_.DatabaseSnapshotBaseName} } elseif ($Snapshot) { # Restore databases from these snapshots Write-Message -Level Verbose -Message "Selected only snapshots" $dbs = $allDbs | Where-Object { $Snapshot -contains $_.Name } $baseDatabases = $dbs | Select-Object -ExpandProperty DatabaseSnapshotBaseName | Get-Unique if ($baseDatabases.Count -ne $Snapshot.Count -and $dbs.Count -ne 0) { Write-Message -Level Warning -Message "Multiple snapshots selected for the same database, skipping" continue } } $opsHash = @{ } foreach ($db in $dbs) { if (-not($db.IsAccessible)) { Write-Message -Level Warning -Message "Database $db is not accessible." continue } if ($db.DatabaseSnapshotBaseName -notin $opsHash.Keys) { if ($snapshot.Count -gt 0) { # just in the need to drop every other snapshot $toDrop = $allDbs | Where-Object { $_.DatabaseSnapshotBaseName -eq $db.DatabaseSnapshotBaseName } $toDrop = $todrop | Select-Object Name $opsHash[$db.DatabaseSnapshotBaseName] = @{ 'from' = $db | Select-Object Name, DatabaseSnapshotBaseName, CreateDate 'drop' = $toDrop } } else { $opsHash[$db.DatabaseSnapshotBaseName] = @{ 'from' = $db 'drop' = @() } } } else { # store each older snapshot in the drop list while enumerating if ($db.CreateDate -gt $opsHash[$db.DatabaseSnapshotBaseName]['from'].CreateDate) { $prev = $opsHash[$db.DatabaseSnapshotBaseName]['from'] $opsHash[$db.DatabaseSnapshotBaseName]['from'] = $db | Select-Object Name, DatabaseSnapshotBaseName, CreateDate $opsHash[$db.DatabaseSnapshotBaseName]['drop'] += $prev } } } foreach ($dbName in $opsHash.Keys) { $drop = @() foreach ($toDrop in $opsHash[$dbName]['drop']) { $drop += $toDrop.Name } $operations += @{ 'from' = $opsHash[$dbName]['from'].Name 'to' = $dbName 'drop' = $drop } } foreach ($op in $operations) { # Check if there are FS, because then a restore is not possible $all_FS = $server.Databases[$op['to']].FileGroups | Where-Object FileGroupType -EQ 'FileStreamDataFileGroup' if ($all_FS.Count -gt 0) { Write-Message -Level Warning -Message "Database $($op['to']) has FileStream group(s). You cannot restore from snapshots" [PSCustomObject]@{ ComputerName = $server.NetName InstanceName = $server.ServiceName SqlInstance = $server.DomainInstanceName Database = $op['to'] Snapshot = $op['from'] Status = 'Error' Notes = "Database $($op['to']) has FileStream group(s). You cannot restore from snapshots" } break } # Get log size and autogrowth $orig_logproperties = $server.Databases[$op['to']].LogFiles | Select-Object Id, Size, Growth, GrowthType # Drop what needs to be dropped $opError = $false if ($op['drop'].Count -gt 1 -and $Force -eq $false) { $warnMsg = @() $warnMsg += "The restore process for $($op['to']) from $($op['from']) needs to drop the following:" foreach ($db in $op['drop']) { $warnMsg += $db } $warnMsg += "Use -Force if you really want to drop these snapshots." Write-Message -Level Warning -Message ($warnMsg -join "`n") break } foreach ($drop in $op['drop']) { if ($Pscmdlet.ShouldProcess($server.name, "Remove db snapshot $drop")) { # skip it if it's the same name if ($drop -ne $($op['from'])) { try { if ($Force) { # snapshot with open transactions cannot be dropped $server.KillAllProcesses($drop) } $null = $server.Query("USE master; DROP DATABASE [$drop]") $status = "Dropped" } catch { Write-Message -Level Warning -Message $_ $operror = $true break } } } } if ($opError) { Write-Message -Level Warning -Message "Errors trying to restore $($op['to']) from $($op['from'])" [PSCustomObject]@{ ComputerName = $server.NetName InstanceName = $server.ServiceName SqlInstance = $server.DomainInstanceName Database = $op['to'] Snapshot = $op['from'] Status = 'Error' Notes = "Failed to drop some snapshots" } break } # Need a proper restore now if ($Pscmdlet.ShouldProcess($server.DomainInstanceName, "Restore db $($op['to']) from $($op['from'])")) { $query = "USE master; RESTORE DATABASE [$($op['to'])] FROM DATABASE_SNAPSHOT='$($op['from'])'" try { if ($Force) { # for whatever reason, a snapshot with open transactions, albeit read-only, block the restore process $server.KillAllProcesses($op['from']) # for a "good" reason, all open transactions on the destination block the restore process $server.KillAllProcesses($op['to']) } $null = $server.Query($query) } catch { $opError = $true $inner = $_.Exception.Message Stop-Function -Message "Original exception: $inner, Query issued: $query, Error: $_.Exception.InnerException.InnerException.Message" -ErrorRecord $_ } } if ($operror) { Write-Message -Level Warning -Message "Errors trying to restore $($op['to']) from $($op['from'])" [PSCustomObject]@{ ComputerName = $server.NetName InstanceName = $server.ServiceName SqlInstance = $server.DomainInstanceName Database = $op['to'] Snapshot = $op['from'] Status = 'Error' Notes = '' } break } # Comparing sizes before and after, need to refresh to see if size foreach ($log in $server.Databases[$op['to']].LogFiles) { $log.Refresh() } foreach ($log in $server.Databases[$op['to']].LogFiles) { $matching = $orig_logproperties | Where-Object ID -EQ $log.ID $changeflag = 0 foreach ($prop in @('Size', 'Growth', 'Growth', 'GrowthType')) { if ($matching.$prop -ne $log.$prop) { $changeflag = 1 $log.$prop = $matching.$prop } } if ($changeflag -ne 0) { Write-Message -Level Verbose -Message "Restoring original settings for log file" $log.Alter() } } [PSCustomObject]@{ ComputerName = $server.NetName InstanceName = $server.ServiceName SqlInstance = $server.DomainInstanceName Database = $op['to'] Snapshot = $op['from'] Status = 'Restored' Notes = 'Remember to take a backup now, and also to remove the snapshot if not needed' } } } } end { Test-DbaDeprecation -DeprecatedOn "1.0.0" -Alias Restore-DbaFromDatabaseSnapshot } } |