functions/Expand-SqlTLogResponsibly.ps1

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
function Expand-SqlTLogResponsibly
{
    #AUTHOR: Cl�udio Silva
    #DATE: 2015-06-13
    #Follow me on twitter @ClaudioESSilva
    
<#

.SYNOPSIS
This module will help you to automatically grow your T-Log database file in a responsible way (preventing generation of too many VLFs).

.DESCRIPTION
As you may already know, having a TLog file with too many VLFs can hurt your database performance in many ways.

Example:
    Too many virtual log files can cause transaction log backups to slow down and can also slow down database recovery, and in extreme cases, even affect insert/update/delete performance.
    References:
        http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/
        http://blogs.msdn.com/b/saponsqlserver/archive/2012/02/22/too-many-virtual-log-files-vlfs-can-cause-slow-database-recovery.aspx
        http://www.brentozar.com/blitz/high-virtual-log-file-vlf-count/

    In order to get rid of this fragmentation we need to growth the file taking the following consideration:
        - How many VLFs are created when we do a grow or when auto-grows hits
    Note: In SQL Server 2014 this algorithm has changed (http://www.sqlskills.com/blogs/paul/important-change-vlf-creation-algorithm-sql-server-2014/)

Atention:
    We are growing in MB instead of GB because of known issue prior to SQL 2012:
        More detail here:
            http://www.sqlskills.com/BLOGS/PAUL/post/Bug-log-file-growth-broken-for-multiples-of-4GB.aspx
        and
            http://connect.microsoft.com/SQLServer/feedback/details/481594/log-growth-not-working-properly-with-specific-growth-sizes-vlfs-also-not-created-appropriately
        or
            https://connect.microsoft.com/SQLServer/feedback/details/357502/transaction-log-file-size-will-not-grow-exactly-4gb-when-filegrowth-4gb

.NOTES
    What this script will NOT DO for you:
        1. Analyse the actual number of VLFs (use DBCC LOGINFO)
        2. T-Log backups (BACKUP LOG <databasename> TO DISK="<path>" or using third-party tools)
        3. Truncate your transaction log (DBCC SHRINKFILE (N'<database_log>', TRUNCATEONLY).
        *************************************************************************************************************
        4. Repeat steps 2 and 3 until you have your T-Log with the desired initial size. Then you may run this script.
           Steps 2 and 3 are likely to be automated in the future.
        *************************************************************************************************************

    You have to make those analysis and take these actions before run this script otherwise only half of the correct process will be made

.LINK
    Understand related problems:
        http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/
        http://blogs.msdn.com/b/saponsqlserver/archive/2012/02/22/too-many-virtual-log-files-vlfs-can-cause-slow-database-recovery.aspx
        http://www.brentozar.com/blitz/high-virtual-log-file-vlf-count/
    
    Known BUG before SQL Server 2012
        http://www.sqlskills.com/BLOGS/PAUL/post/Bug-log-file-growth-broken-for-multiples-of-4GB.aspx
        http://connect.microsoft.com/SQLServer/feedback/details/481594/log-growth-not-working-properly-with-specific-growth-sizes-vlfs-also-not-created-appropriately
        https://connect.microsoft.com/SQLServer/feedback/details/357502/transaction-log-file-size-will-not-grow-exactly-4gb-when-filegrowth-4gb

.PARAMETER SqlServer
    Represents the name/ip of the instance where the database(s) that you want to grow exists
     
.PARAMETER Databases
    This is the list of databases within Instance that this script will grow their t-log files.
    You can pass only one or many. Can be input by pipeline. (view examples)

.PARAMETER TargetLogSizeMB
    Represents the target log size that log will grow. Expressed in MB.
    
.PARAMETER IncrementSizeMB
    Represents the size of each grow will perform. Expressed in MB.
    If you don't provide this parameter the value will be calculated automatically. Otherwise, the input value will be compared with the suggested
    for your target size. If it is different will ask which one you would like to assume.

.PARAMETER LogFileId
    If you want to grow a secondary, tertiary, other T-Log file you can mention the log file number (FileId column from DBCC LOGINFO output).
    When not provided, will do on the first T-Log file.

.NOTES
Author: Cl�udio Silva (@claudioessilva)
Requires: ALTER DATABASE permission
Limitations: On SQL Server 2005 cannot validate freespace on drive where log file resides.

dbatools PowerShell module (https://dbatools.io, clemaire@gmail.com / claudiosil100@gmail.com)
Copyright (C) 2016 Cl�udio Silva

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.

.EXAMPLE
    Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 50000
    This is the simplest example. The increment value will be calculated and will grow the T-Log of 'Test' database on 'Localhost' instance
    to 50000 MB.

.EXAMPLE
    Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 10000 -IncrementSizeMB 200
    Grows the T-Log of 'Test' database on 'Localhost' instance to 1000MB. The increment value will be asked if want to use the input value or
    the suggested one (calculated automatically)

.EXAMPLE
    Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 10000 -LogFileNumber 9
    Grows the T-Log with FielId 9 of 'Test' database on 'Localhost' instance to 10000MB.

.EXAMPLE
    Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases (gc D:\DBs.txt) -TargetLogSizeMB 50000
    Grows the T-Log of the databases specified in the file 'D:\DBs.txt' on 'Localhost' instance to 50000MB.

.EXAMPLE
    Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases @("DB1", "DB2") -TargetLogSizeMB 50000
    Grows the T-Log of the databases DB1 and DB2 on 'Localhost' instance to 50000MB.

.EXAMPLE
    Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 50000 -Verbose
    Use -Verbose to view in detail all actions performed by this script
#>

    [CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'Medium')]
    param (
        [parameter(Position = 1, Mandatory = $true)]
        [Alias("ServerInstance", "SqlInstance")]
        [object]$SqlServer,
        [parameter(Position = 3)]
        [System.Management.Automation.PSCredential]$SqlCredential,
        [parameter(Position = 4, Mandatory = $true)]
        [int]$TargetLogSizeMB,
        [parameter(Position = 5)]
        [int]$IncrementSizeMB = -1,
        [parameter(Position = 6)]
        [int]$LogFileId = -1
    )
    
    DynamicParam { if ($SqlServer) { return Get-ParamSqlDatabases -SqlServer $SqlServer -SqlCredential $SourceSqlCredential } }
    
    BEGIN
    {
        Write-Verbose "Set ErrorActionPreference to Inquire"
        $ErrorActionPreference = 'Inquire'
        
        #Convert MB to KB (SMO works in KB)
        Write-Verbose "Convert variables MB to KB (SMO works in KB)"
        [int]$TargetLogSizeKB = $TargetLogSizeMB * 1024
        [int]$LogIncrementSize = $incrementSizeMB * 1024
        [int]$SuggestLogIncrementSize = 0
        [bool]$LogByFileID = if ($LogFileId -eq -1)
        {
            $false
        }
        else
        {
            $true
        }
        
        #Set base information
        Write-Verbose "Initialize the instance '$SqlServer'"
        
        $server = Connect-SqlServer -SqlServer $SqlServer -SqlCredential $SqlCredential
    }
    
    PROCESS
    {
        try
        {
            $databases = $psboundparameters.Databases
            
            [datetime]$initialTime = Get-Date
            
            #control the iteration number
            $i = 0;
            
            #go through all databases
            Write-Verbose "Processing...foreach database..."
            foreach ($db in $Databases)
            {
                $i += 1
                
                #set step to reutilize on logging operations
                [string]$step = "$i/$($Databases.Count)"
                
                if ($server.Databases[$db])
                {
                    Write-Progress `
                                   -Id 1 `
                                   -Activity "Using database: $db on Instance: '$SqlServer'" `
                                   -PercentComplete ($i / $Databases.Count * 100) `
                                   -Status "Processing - $i of $($Databases.Count)"
                    
                    #Validate which log that file will grow
                    if ($LogByFileID)
                    {
                        $logfile = $server.Databases[$db].LogFiles.ItemById($LogFileId)
                    }
                    else
                    {
                        $logfile = $server.Databases[$db].LogFiles[0]
                    }
                    
                    Write-Verbose "$step - Use log file: $logfile"
                    $CurrSize = $logfile.Size
                    
                    Write-Verbose "$step - Log file current size: $([System.Math]::Round($($CurrSize/1024.0), 2)) MB "
                    [long]$requiredSpace = ($TargetLogSizeKB - $CurrSize)
                    
                    Write-Output $logfile
                    
                    Write-Verbose "Verifying if exists sufficient space ($([System.Math]::Round($($requiredSpace / 1024.0), 2))MB) on the volume to performe this task"
                    
                    #Only available from 2008 R2 towards... maybe validate the version and issue a warning saying "can't verify volume free space"
                    if ($requiredSpace -gt $logfile.VolumeFreeSpace)
                    {
                        Write-Output "There is not enough space on volume to perform this task. `r`n" `
                                     "Available space: $([System.Math]::Round($($logfile.VolumeFreeSpace / 1024.0), 2))MB;`r`n" `
                                     " Required space: $([System.Math]::Round($($requiredSpace / 1024.0), 2))MB;"
                        return
                    }
                    else
                    {
                        # SQL 2005 or lower version. The "VolumeFreeSpace" property is empty
                        if ($logfile.VolumeFreeSpace -eq $null)
                        {
                            $choice = ""
                            while ($choice -notmatch "[y|n]")
                            {
                                $choice = read-host "Cannot validate freespace on drive where log file resides? Do you wish to continue (Y/N)"
                            }
                            
                            if ($choice.ToLower() -eq "n")
                            {
                                Write-Output "You have cancelled the execution"
                                #end script
                                return
                            }
                            
                        }
                        
                        if ($CurrSize -ige $TargetLogSizeKB)
                        {
                            Write-Output "$step - [INFO] The T-Log file '$logfile' size is already equal or greater than target size - No action required"
                        }
                        else
                        {
                            Write-Verbose "$step - [OK] There is sufficient free space to perform this task"
                            
                            # If version greater or equal 2012
                            if ($server.Version.Major -ge "11")
                            {
                                switch ($TargetLogSizeMB)
                                {
                                    { $_ -le 64 } { $SuggestLogIncrementSize = 64 }
                                    { $_ -gt 64 -and $_ -lt 256 } { $SuggestLogIncrementSize = 256 }
                                    { $_ -gt 256 -and $_ -lt 1024 } { $SuggestLogIncrementSize = 512 }
                                    { $_ -gt 1024 -and $_ -lt 4096 } { $SuggestLogIncrementSize = 1024 }
                                    { $_ -gt 4096 -and $_ -lt 8192 } { $SuggestLogIncrementSize = 2048 }
                                    { $_ -gt 8192 -and $_ -lt 16384 } { $SuggestLogIncrementSize = 4096 }
                                    { $_ -ge 16384 } { $SuggestLogIncrementSize = 8192 }
                                }
                            }
                            else # 2008 R2 or under

                            {
                                switch ($TargetLogSizeMB)
                                {
                                    { $_ -le 64 } { $SuggestLogIncrementSize = 64 }
                                    { $_ -gt 64 -and $_ -lt 256 } { $SuggestLogIncrementSize = 256 }
                                    { $_ -gt 256 -and $_ -lt 1024 } { $SuggestLogIncrementSize = 512 }
                                    { $_ -gt 1024 -and $_ -lt 4096 } { $SuggestLogIncrementSize = 1024 }
                                    { $_ -gt 4096 -and $_ -lt 8192 } { $SuggestLogIncrementSize = 2048 }
                                    { $_ -gt 8192 -and $_ -lt 16384 } { $SuggestLogIncrementSize = 4000 }
                                    { $_ -ge 16384 } { $SuggestLogIncrementSize = 8000 }
                                }
                                
                                if (($IncrementSizeMB % 4096) -eq 0)
                                {
                                    Write-Output "Your instance version is below SQL 2012, remember the known BUG mentioned on HELP. `r`nUse Get-Help Expand-SqlTLogFileResponsibly to read help`r`nUse a different value for incremente size`r`n"
                                    #TODO: Write-error???
                                    return
                                }
                            }
                            Write-Verbose "Instance $server version: $($server.Version.Major) - Suggested TLog increment size: $($SuggestLogIncrementSize)MB"
                            
                            # SMO use values in KB
                            $SuggestLogIncrementSize = $SuggestLogIncrementSize * 1024
                            
                            # If default will use $SuggestedLogIncrementSize
                            if ($IncrementSizeMB -eq -1)
                            {
                                $LogIncrementSize = $SuggestLogIncrementSize
                            }
                            else
                            {
                                if ($PSCmdlet.ShouldProcess("Confirm increment value", `
                                "The input value is $([System.Math]::Round($LogIncrementSize/1024, 0))MB. However the suggested value for increment is $($SuggestLogIncrementSize/1024)MB.`r`n Do you want to use the suggested value of $([System.Math]::Round($SuggestLogIncrementSize/1024, 0))MB insted of $([System.Math]::Round($LogIncrementSize/1024, 0))MB",
                                "Choose increment value:"))
                                {
                                    $LogIncrementSize = $SuggestLogIncrementSize
                                }
                            }
                            Write-Output "Chunk size: $($LogIncrementSize/1024)MB"
                            
                            #start grow file
                            Write-Verbose "$step - While current size less than wanted log size"
                            while ($CurrSize -lt $TargetLogSizeKB)
                            {
                                
                                Write-Progress `
                                               -Id 2 `
                                               -ParentId 1 `
                                               -Activity "Growing file $logfile on '$db' database" `
                                               -PercentComplete ($CurrSize / $TargetLogSizeKB * 100) `
                                               -Status "Remaining - $([System.Math]::Round($($($TargetLogSizeKB - $CurrSize) / 1024.0), 2)) MB"
                                
                                Write-Verbose "$step - Verifying if the log can grow or if has already the desired space allocated"
                                if (($TargetLogSizeKB - $CurrSize) -lt $LogIncrementSize)
                                {
                                    Write-Verbose "$step - Log size is lower than the increment size. Setting current size equals $TargetLogSizeKB"
                                    $CurrSize = $TargetLogSizeKB
                                }
                                else
                                {
                                    Write-Verbose "$step - Grow the $logfile file in $([System.Math]::Round($($LogIncrementSize / 1024.0), 2)) MB"
                                    $CurrSize += $LogIncrementSize
                                }
                                
                                #When -WhatIf Switch, do not run
                                if ($PSCmdlet.ShouldProcess("$step - File will grow to $([System.Math]::Round($($CurrSize/1024.0), 2)) MB", "This action will grow the file $logfile on database $db to $([System.Math]::Round($($CurrSize/1024.0), 2)) MB .`r`nDo you wish to continue?", "Performe grow"))
                                {
                                    Write-Verbose "$step - Set size $logfile to $([System.Math]::Round($($CurrSize/1024.0), 2)) MB"
                                    $logfile.size = $CurrSize
                                    
                                    Write-Verbose "$step - Applying changes"
                                    $logfile.Alter()
                                    Write-Verbose "$step - Changes have been applied"
                                    
                                    #Will put the info like VolumeFreeSpace up to date
                                    $logfile.Refresh()
                                }
                            }
                            Write-Verbose "`r`n$step - [OK] Growth process for logfile '$logfile' on database '$db', has been finished."
                            
                            Write-Verbose "$step - Grow $logfile log file on $db database finished"
                        }
                    } #else space available
                }
                else #else verifying existance

                {
                    Write-Output "Database '$db' not exists on instance '$SqlServer'"
                }
            }
        }
        catch
        {
            Write-Output "Logfile $logfile on database $db not processed. Error: $($_.Exception.Message). Line Number: $($_InvocationInfo.ScriptLineNumber)"
        }
    }
    
    END
    {
        $server.ConnectionContext.Disconnect()
        Write-Output "Process finished $((Get-Date) - ($initialTime))"
    }
}