Show TOC

Function documentationChecksums

 

You use this function to check checksums for completeness of data in Retention Warehouse. Create checksums for field values of a record of archive files. You can then compare the checksums of the data from the legacy system and the corresponding data from the WebDAV hierarchy in the ILM-enabled storage system.

Prerequisites

  • The prerequisite for using this function is the SAP_BC_ILM_CHECK role.

  • The RW Repository must be maintained. To do so, execute the transactions IWP_REPOS and IWP_REPOS_OT or, in the area menu IWP_IMG, select the option Load Repository from Metadata. You can call up this activity in the system decommissioning cockpit.

  • The object that you want to check in the checksums function, as well as the relevant tables and fields, needs to be active in at least one audit area. Use transaction ILMARA (processing of audit areas) to assign objects with tables and fields to audit areas.

Features

You use the checksums function to analyze data that has been archived and transferred to the Retention Warehouse system before and after using rules for file conversion. You use the checksums comparison to determine whether the data from a legacy system has been transferred completely (and correctly) to Retention Warehouse. To be able to compare checksums, you need to execute at least two analyses with the same criteria in Retention Warehouse: An analysis of the archived data that has been transferred from the legacy system to Retention Warehouse before file conversion takes places, and an analysis of the same data record after the files have been converted and stored successfully. To perform a checksums analysis, carry out the following steps:

Define an Analysis Variant

You need an analysis variant to perform a checksums analysis. You use the analysis variant to define the data areas and fields that you want to include in the analysis. This is how you create new variant:

  1. Execute the checksums function (call it up in the system decommissioning cockpit or use transaction ILMCHECK) and enter the object for which you want to perform an analysis.

  2. Define a new variant as described below:

    On the New Variant screen, enter a name for the variant and select the table for which you want to create the checksums from the dropdown menu. The dropdown menu contains only the tables for which an object has been activated in an audit area (transaction ILMARA). Depending on which table you have selected, a list of fields that were set to "active" in an audit area is displayed in the Field Selection table.

  3. Select the fields you want to you use to calculate checksums and those fields you want to display for selection at a later time so that you can restrict your data for the checksums run. If a field is available for selection under Summation as well as under Selection Field, you can select only one checkbox. If you select the Summation checkbox, the Selection Field checkbox is deactivated automatically.

  4. To save your variant, choose Save.

Perform Checksums Analysis

If you have created at least one analysis variant, you can perform a checksums analysis.

Note Note

Important: First you need to analyze the data copied from the legacy system (prior to file conversion). You perform file conversion as the second and as the third step, you analyze the data in the storage system. After file conversion, you can no longer analyze data from before the file conversion.

End of the note.

Step 1 - Perform checksums analysis of the data prior to file conversion:

  1. After you have saved this variant, choose Perform Analysis. If you want to use an existing variant, execute the transaction ILMCHECK. On the initial screen, enter an object, select an existing variant and then select Execute.

  2. On the Perform Analysis selection screen, enter the system ID and the client of the legacy system that contains the data you want to analyze.

  3. Select the Original System radio button if you want to use archive files that have been transferred from the legacy system to Retention Warehouse but which have not yet been converted. This data is still in the file system.

  4. When you select data, you can restrict the selection further to determine a specific data area for creating a checksum. You do this with the selection fields you have specified in the variant.

  5. If you want to calculate a checksum for large volumes of data, you can execute the session in the background by selecting the In Background checkbox.

Step 2 - Execute file conversion

After you have executed the first checksums run, you need to convert the files for the application of retention rules and then store them in an Information Lifecycle Management-enabled storage system. For more information, see File Conversion.

Step 3 - Perform checksums analysis of the data after file conversion:

  1. On the initial screen for transaction ILMCHECK, enter an object, select the same variant as above, and choose Perform Analysis.

  2. On the Perform Analysis selection screen, enter the system ID and the client of the legacy system that contains the data you want to analyze.

  3. Select the Store radio button if you want to use archive data that has already been converted and stored in an Information Lifecycle Management-enabled storage system.

  4. You can fine tune your data selection further, if necessary.

  5. If you want to calculate a checksum for large volumes of data, you can execute the session in the background by selecting the In Background checkbox.

Checksums Results

When the analysis run is over, the system displays the results of the checksums analyses. To call up the checksums results directly, execute transaction ILMCHECK, enter an existing variant, and then choose Display Results. The list of results always refers to a specific combination of a system and a client. Only analyses that are without errors are included. If the results are the same, the newer analysis is preferred. Checksums are categorized according to the selection fields of the analysis variant.

The table Checksums Results - Summary of All Analyses contains the final checksums results of all analyses that were performed with this variant. You can compare the data here:

  • Number of Entries Original/Storage Location: Both of these columns contain the number of objects in both checksums analyses: Original system (prior to file conversion, compare Step 1) and storage system after file conversion, compare Step 3). If all data has been converted and stored correctly, the values in both columns should be the same.

  • Total of Field Values: The table contains two columns for each summation, Original System and Storage. Each column contains the sum of all field values prior to or after file conversion (for example, the sum of the prices for all flights of a specific carrier), so that you can compare all values. This means: If all values are equal, the data has been converted and stored correctly.

The table Completed Analyses displays a list of analyses that were performed with a specific variant. The individual columns contain information about each analysis, for example, the user who performed it, the start and end time, whether it was completed, and with which settings it was performed.

  • Check Status and Comment: After completion of the analysis, a responsible person can set the status of the analysis to Completed. This person should have extensive knowledge of the archived data, the transfer of the data from the legacy system to the Retention Warehouse system, and the file conversion process. After file conversion it is not possible to go back and perform a checksums analysis of the data as it was prior to the conversion. The commentary field is a free text field for notes and commentaries about the analysis.

  • Display Details: If you want to display details about a specific analysis run, you select these runs and then select Display Details. The new screen displays the number of object instances as well as the sum of all totaled field values that you selected for the analysis run. If only one analysis exists, then these are the same values as in the comparison table Checksums Result.

You can also delete or continue a selected analysis run. Continuing makes sense only if new data has been added to the file system or the archive.