CChkSGFiles.ErrCheckDbPages function

Last modified: February 22, 2013

Applies to: Exchange Server 2003 | Exchange Server 2007 | Exchange Server 2010 | Exchange Server 2013

Validates a range of pages in a specified database.

C#
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Vitual ERRErrCheckDbPages 
(
    Const ULONGiDb,
    Const VOID * const pvPageBuffer,
    Const ULONGcbPageBuffer,
    PAGE_INFOrgPageInfo[],
    Const ULONGcPageInfo,
    Const ULONGulFlags = NO_FLAGS
);

iDb

Input parameter. An index into the array of databases specified in the rgwszDb[] parameter to the ErrInit function. The database indexed by this parameter will be checked.

pvPageBuffer

Input parameter. A pointer to a buffer containing one or more database pages to be checked. The size of the buffer must be a multiple of the database page size, as returned in the pcbDbPageSize parameter by the ErrCheckDbHeaders function. The calling application must fill the buffer with the database page contents before calling ErrCheckDbPages.

cbPageBuffer

Input parameter. The size of the pvPageBuffer parameter, in bytes. This value must be a multiple of the database page size, as returned in the pcbDbPageSize parameter by the ErrCheckDbHeaders function.

rgPageInfo[]

Input/output parameter. An array of PAGE_INFO structures that ErrCheckDbPages fills with detailed results of each database page that is checked. The array must have one element for each database page passed in the pvPageBuffer parameter, and the ulPgno field in each PAGE_INFO structure must be set to the logical page number that corresponds to the database page. For more information, see "Remarks" later in this topic.

cPageInfo

Input parameter. The number of entries in the rgPageInfo[] array. This value must be equal to the number of database pages passed in the pvPageBuffer parameter.

ulFlags

Optional input parameter. This value is reserved for future use. The value passed in this parameter should be 0 (zero).

An error code from the ERR enumeration.

Note that you need to have specified the database in the array of databases passed to the ErrInit function. Also, ErrCheckDbHeaders must be called before ErrCheckDbPages.

The calling application must allocate a memory buffer that is large enough to hold the database pages to be checked. The application is responsible for filling the buffer with the contents of one or more such database pages.

The calling application must call ErrCheckDbHeaders before calling ErrCheckDbPages. This function can be called as many times as necessary to cover all the pages in all database files that are to be checked.

In the rgPageInfo[] parameter, each element returned contains information about the database page in a PAGE_INFO structure. If the ErrCheckDbPages function returns an error, the application should check each PAGE_INFO structure to determine on which page the error was found. For example, comparing the checksumActual and checksumExpected values will indicate whether a checksum error was detected on that database page.

If ErrCheckDbPages detects any errors in the database content, it will create a Windows Error event log entry.

The CChkSGFiles object determines whether all the databases registered with the ErrInit function were actually checked. Specifically, CChkSGFiles uses the ErrCheckDbPages function to determine whether the same number of database pages indicated by ErrCheckDbHeaders were actually verified. If the correct number of pages in each database were not successfully checked, the ErrTerm function returns an error.

If you're using CHKSGFILES in a multithreaded application, you can call the ErrCheckDbPages function in the multithreaded portion of the application. Note that ErrCheckDbPages is typically called multiple times for each database that is checked.

Exchange 2013 only includes a 64-bit version of the CHKSGFILES API.

The account that the application is running under must have read permissions to the database and log files that are to be checked.

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