This chapter describes configuring DIVArchive Checksum Support and includes the following information:
You configure the Checksum Support functions through the Configuration Utility using the Engineer account. The following sections describe how to adjust the settings for each option.
You must use the Engineer account in the Configuration Utility to access and adjust the Global Checksum Parameters located under the Manager Setting tab. Each of the global parameters affects all Checksum Support settings throughout the system. The following options are available:
This setting enables (check box selected) or disables (check box deselected) the Checksum Support features throughout DIVArchive. The default setting is enabled (selected).
There are several checksum algorithms supported by the system including MD2, MD5, SHA, SHA1, MDC2, and RIPEMD160. DIVArchive uses MD5 as the default checksum.
Each checksum type is associated with an ID Number. you use the menu list to change the default type and select the type of checksum desired.
The ID Number identifies the Checksum Type requested in the configuration as follows:
MD2 is ID Number 1
MD5 is ID Number 2
SHA is ID Number 3
SHA-1 is ID Number 4
MDC2 is ID Number 5
RIPEMD160 is ID Number 6
This parameter sets the number of times the system will retry the operation after a failed checksum. The default setting is one retry. Enter the number of retries allowable for your data and system in the Manager: Number of retries following failed checksum field. Oracle recommends leaving this setting at the default value.
This parameter distinguishes whether the retry (after a failed checksum) is attempted on the same drive (check box deselected), or if the system should attempt the operation using a different drive (check box selected). The default setting for this parameter uses the same drive (check box deselected).
You adjust the Checksum Support configuration for sources and destinations through the Configuration Utility System tab. In the Sources and Destinations frame, double-click the Source or Destination requiring Checksum Support configuration. The Edit Source and Destinations Entry dialog box appears with several Checksum Support configuration options. These options are mainly associated with the Genuine Checksum Type.
The following list describes the options available:
You must use the External Checksum Source (Yes option) for the system to read the Checksum from the external source providing the file. This initiates an immediate checksum calculation to compare the checksums and verify the initial transfer. Selecting the No option disables Genuine Checksum support from external sources.
You use the menu list to select the Checksum Type. All supported checksum types are listed. The Checksum Type and GC Mode (see the following description) must match the settings implemented at the Source.
The Genuine Checksum is only used for the first verification. Therefore, the checksum type selected is only used once and then discarded. Beyond the initial use of the selected checksum type (after this transfer), the default type is used.
You use the menu list to select the Genuine Checksum Mode. This notifies the Actor of the format of the files that contain the checksum data.
When Verify Following Archive (VFA) is turned on (check box selected), performing the initial transfer from the source results in a read-back operation. Therefore, the data is read twice for verification. After the data is read twice, the two checksums are compared. If they are the same then verification is complete. If they are not identical then verification has failed.
Verify Following Archive is not compatible with Genuine Checksum (GC) or complex objects. There is no need to use VFA when GC is being used because the checksum is already verified. The Genuine Checksum must be turned off to gain access to the VFA check box. If GC is turned on, the check box will be grayed out and not selectable.
When Verify Following Restore (VFR) is turned on (check box selected), performing the final transfer to the destination results in a read-back operation. Therefore, the data is read twice for verification. After the data is read twice, the two checksums are compared. If they are the same then verification is complete. If they are not identical then verification has failed. The setting of GC has no bearing on the VFR setting.
Verify Following Restore is not compatible with complex objects or the -axf option.Verify Following Restore was designed to read back the restored content from a video server to confirm that it is not corrupt. Using the -axf option does not create a checksum verifiable restore. It creates an object export that is encompassed in an AXF wrapper. The VFR and -axf options are mutually exclusive and should not be part of the same workflow.
You configure Checksum Support for Arrays and Disks through the Configuration Utility Disks tab. You can turned on or off Verify Write (VW) functionality either on an array basis or disk by disk.
VW applies when you write to the final storage location in DIVArchive. When turned ON, the system will perform a read-back of what was just written and compare the checksums for verification.
The VW column in both the Arrays frame and Disks frame indicates whether the Verify Write function is on or off for the particular array and disk. The default setting is OFF.
If there is nothing defined in the VW column on the Disk frame the system will use the setting defined in the Array VW column.
To override the setting defined in the Array VW column for a specific disk, you select the disk requiring configuration in the Disks frame and click Edit located at the top of the frame.
When the Edit Disks Entry dialog box appears, use the Verify Write menu list to select ON, OFF, or NONE (blank selection). If NONE is selected, Verify Write uses the setting identified in the array for this particular disk.
The selection made in the Edit Disk Entry dialog box is reflected in the Disks VW column.
You can also configure Verify Write for Groups. The VW column displays in the Groups frame of the Configuration Utility. This is the only place where configuration of Verify Write is available for the Groups.
Similar to the configuration for disks, select the group requiring configuration. Click Edit and select ON or OFF using the Verify Write menu list. Your selection is reflected in the Groups VW column.
When DIVArchive writes a file to a particular group, the setting for that group is applied to the file. The default setting for groups is OFF.
You can configure Verify Tape for Actors. Similar to the configuration for disks and groups, you select the Actor requiring configuration, click Edit, and then select Yes or No using the Verify Tape menu list.
This setting defines whether the Actor is automatically selected for the Verify Tape workflow. By default, all Actors are included, but you can exclude if necessary.
There are two additional Genuine Checksum modes as follows:
This mode enables DIVArchive to archive all files and subfolders in a specified AXF file while comparing their checksum values against known values stored in the AXF file. This workflow is typically combined with a Restore request with -axf in the Request Options.
This mode enables DIVArchive to archive all files and subfolders in a specified folder while comparing their checksum values against known values stored in an external checksum file.
There are specific requirements and limitations when using the AXF Genuine Checksum Mode as follows:
The AXF file containing the files to be archived must contain checksum information for each file.
The checksums must be the expected type as specified in the configuration.
This workflow only works with AXF requests generated by DIVArchive.
Verify Following Restore (VFR) is not compatible with the -axf option.
VFR was designed to read back the restored content from a video server to verify it has not been corrupted. Using the -axf option does not create a real restore, rather an object export in an AXF wrapper. These options are mutually exclusive and should not be part of the same workflow.
Use the following procedure to configure AXF Genuine Checksum Mode in the DIVArchive Configuration utility:
Create a new Source/Destination entry with the Source Type set to either DISK, FTP_STANDARD, or EXPEDAT as appropriate.
If you are required specify an appropriate Root Path, this path along with the input files specified during the Archive request, is used in determining the location of the checksum file.
For example, if the Source Type is DISK, you can set the Root Path to D:\root. If the Source Type is FTP_STANDARD, you can set the Root Path to /root.
Set the External Checksum Source to YES.
Set the Checksum Type to the expected checksum type (for example, MD5).
Set the GC Mode to AXF.
Click the OK button.
Notify the Manager of the configuration by selecting Tools, then Notify Manager from the menu.
There are specific requirements and limitations when using the TEXT Genuine Checksum Mode as follows:
A checksum file must be present in the folder specified by the Root File Path.
Checksum files must end with a .md5 file extension.
The checksum file name (excluding the extension) must be associated with the folder name that contains all files to be archived. This folder must exist.
For example, if the checksum file is D:\Data\Video\NewTitle.md5, then all files located in the D:\Data\Video\NewTitle folder will be archived.
The checksum file must be present in the folder parent to the folder specified by the Root File Path.
For a file to be archived with the Genuine Checksum value, the file must be referenced with a corresponding checksum within the checksum file.
Absolute path names are supported on both Windows and Linux to a maximum of 4000 characters. Relative path names are limited to 256 characters on Windows systems (only).
Linux paths, file names, and commands are case-sensitive.
Only ASCII, non-UTF-8 encoded checksum files are supported.
The format of the checksum file is that each line begins with an MD5 checksum, followed by 2 spaces, and then the file path to the referenced file.
Use the following procedure to configure TEXT Genuine Checksum Mode in the DIVArchive Configuration utility:
Create a new Source/Destination entry with Source Type set to either DISK or FTP_STANDARD.
Specify an appropriate Root Path. This path, along with the input files, specified during the Archive request is used in determining the location of the checksum file (see Selecting the Root File Path for further details).
For example, if the Source Type is DISK, you can set the Root Path to D:\Data. If the Source Type is FTP_STANDARD, you can set the Root Path to /Data.
Set the External Checksum Source to YES.
Set the Checksum Type to MD5.
Set the GC Mode to TEXT.
Click the OK button.
Notify the Manager of the configuration by selecting Tools, then Notify Manager from the menu.
The Root File Path must point to the folder containing the checksum file. Therefore, you must set the correct file and folder paths in the Source/Destination and Archive request form so the checksum file can be located. For example, if the checksum file is located in D:\Data\Video\NewTitle.md5 (or /Data/Video/NewTitle.md5 for FTP type), you set the appropriate file and folder paths as follows: