监视 SQL Server 数据文件中的可用空间

Question

监视 SQL Server 数据文件中的可用空间

Bua*_*aXD 9 monitoring sql-server perfmon disk-space

我已手动将 mdf/ndf 文件调整为较大的大小，以避免对 SQL Server 数据库进行自动增长操作。由于文件较大，磁盘分区上的可用空间很少，系统管理员不断提醒我空间不足。

因为我调整了它们的大小，所以数据文件中有很多可用空间，但在查看文件大小/磁盘可用空间时不会注意到它。

如何监控数据文件的实际使用百分比？我更喜欢使用 perfmon 计数器。我担心当文件真的用完空间时，SQL Server 将无法分配足够的空间并且会崩溃。

Answer 1

当您可以从简单查询中获取性能计数器时，不确定为什么要为此使用性能计数器。事实上，虽然您可以从性能计数器 ( Log File(s) Size (KB)/ Log File(s) Used Size (KB))获取有关日志文件的这些信息，但没有这样的计数器来计算数据文件中使用了多少空间。

;WITH f AS 
(
  SELECT name, size = size/128.0 FROM sys.database_files
),
s AS
(
  SELECT name, size, free = size-CONVERT(INT,FILEPROPERTY(name,'SpaceUsed'))/128.0
  FROM f
)
SELECT name, size, free, percent_free = free * 100.0 / size
FROM s;

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Answer 2

Kin*_*hah 7

我有另一种方法来主动监视数据文件空间并在可用空间低于特定百分比时使用 SQL Alert 发出警报。

基础知识是

在 sys.messages 中创建用户定义的错误消息。这将被 sql 代理警报使用。

-- User-defined error messages can be an integer between 50001 and 2147483647. 
EXEC sp_addmessage 
  @msgnum=911421, -- 911DBA
  @severity=1,    -- Informational message not generated by DB Engine       
  @msgtext=N'Data files are %d percent full in database %s.'

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现在创建一个 SQL 代理作业。确保set @threshold = 20 --->>>>>>>>>>>>>>>>> CHANGE HERE <<<<<<<<<<<<<<<<<<<<<---在下面的脚本中进行更改。我已经把他作为一个非常低的门槛，只是为了模拟警报。安排作业每 30 分钟运行一次（根据您的需要进行更改）。

    if object_id('tempdb..#dbserversize') is not null
    DROP TABLE #dbserversize;

    create table dbo.#dbserversize (
     [id] int identity (1,1)
     ,[databaseName] sysname
    ,[Drive]    varchar(3)
    ,[Logical Name] sysname
    ,[Physical Name]    varchar(max)
    ,[File Size MB] decimal(38, 2)
    ,[Space Used MB]    decimal(38, 2)
    ,[Free Space]   decimal(38, 2)
    ,[%Free Space]  decimal(38, 2)
    ,[Max Size] varchar(max)
    ,[Growth Rate]  varchar(max)
    )

    declare @id int
    declare @threshold int
    declare @dbname sysname

    declare @sqltext nvarchar(max)

    declare @freespacePct int

    set @threshold = 20   --->>>>>>>>>>>>>>>>> CHANGE HERE <<<<<<<<<<<<<<<<<<<<<---

    select @dbname = min(name) from sys.databases where database_id > 4 and [state] = 0 

    while @dbname is not NULL

    begin
        select @dbname = name from sys.databases where name = @dbname and database_id > 4 and [state] = 0 
            --- Modified from Erin's blog : Proactive SQL Server Health Checks, Part 1 : Disk Space
            --- source http://sqlperformance.com/2014/12/io-subsystem/proactive-sql-server-health-checks-1
        set @sqltext =  ' use '+@dbname+';'+' 
            insert into dbo.#dbserversize
            select '''+@dbname+''' as [databaseName]
                ,substring([physical_name], 1, 3) as [Drive]
                ,[name] as [Logical Name]
                ,[physical_name] as [Physical Name]
                ,cast(CAST([size] as decimal(38, 2)) / 128.0 as decimal(38, 2)) as [File Size MB]
                ,cast(CAST(FILEPROPERTY([name], ''SpaceUsed'') as decimal(38, 2)) / 128.0 as decimal(38, 2)) as [Space Used MB]
                ,cast((CAST([size] as decimal(38, 0)) / 128) - (CAST(FILEPROPERTY([name], ''SpaceUsed'') as decimal(38, 0)) / 128.) as decimal(38, 2)) as [Free Space]
                ,cast(((CAST([size] as decimal(38, 2)) / 128) - (CAST(FILEPROPERTY([name], ''SpaceUsed'') as decimal(38, 2)) / 128.0)) * 100.0 / (CAST([size] as decimal(38, 2)) / 128) as decimal(38, 2)) as [%Free Space]
                ,case 
                    when cast([max_size] as varchar(max)) = - 1
                        then ''UNLIMITED''
                    else cast([max_size] as varchar(max))
                    end as [Max Size]
                ,case 
                    when is_percent_growth = 1
                        then cast([growth] as varchar(20)) + ''%''
                    else cast([growth] as varchar(20)) + ''MB''
                    end as [Growth Rate]
                from sys.database_files
                where type = 0 -- for Rows , 1 = LOG'
            --print @sqltext
            exec (@sqltext)


            select @dbname = min(name) from sys.databases where name > @dbname and database_id > 4 and [state] = 0 
    end


    --- delete the entries that do not meet the threshold 

    delete from dbo.#dbserversize
    where [%Free Space] < @threshold;


    --select * from dbo.#dbserversize

    --- NOW Raise errors for the databases that we got flagged up

    while exists (select null from dbo.#dbserversize)
    begin

        select top 1 @id = id,
                    @dbname = databaseName,
                    @freespacePct = [%Free Space]
                from dbo.#dbserversize;


            RAISERROR(911421, 10,1,@freespacePct, @dbname) with LOG;

            delete from dbo.#dbserversize where id = @id;

    end

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现在创建一个警报来响应911421错误号。

USE [msdb]
GO
EXEC msdb.dbo.sp_add_alert @name=N'MDF file alert', 
        @message_id=911421, 
        @severity=0, 
        @enabled=1, 
        @delay_between_responses=1800, 
        @include_event_description_in=0, 
        @job_id=N'019c4770-865b-406b-894e-72a1ff34f732'
GO
EXEC msdb.dbo.sp_add_notification @alert_name=N'MDF file alert', @operator_name=N'Notify 911 DBA for MDF files getting full', @notification_method = 1
GO

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