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Method To Inform User To Perform A Specific Type Of Backup Operation Disclosure Number: IPCOM000204419D
Publication Date: 2011-Feb-24
Document File: 3 page(s) / 52K

Publishing Venue

The Prior Art Database


Disclosed is a method that allows a data backup application to detect that a data storage filer has migrated from a non-Unicode version of its snapshot difference API to a version that supports Unicode, and notifies the user that a full backup is needed. The user can, at their discretion, schedule the one-time full backup at an optimal time or turn off the warning message.

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Method To Inform User To Perform A Specific Type Of Backup Operation

If a data storage filer, such as a Network Attached Storage (NAS) device includes a snapshot difference API, a backup application can use this API to enumerate the differences between two snapshots of the filer's file system. These differences include files that were created, changed or deleted. This information can be used by the backup application to determine:

• Which files need to be backed up (new or changed files)
• Which files need to be expired from the backup inventory (deleted files)

Note: Throughout the rest of this document terms such as "file changes" or "changed files" will be used to refer to files that are created, changed or deleted.

If a filer's snapshot difference API originally supported only 7-bit American Standard Code for Information Interchange (ASCII) characters in file names, then backup of files with non 7-bit ASCII ("Unicode") characters in file names occurred only during the first snapshot difference backup operation. For subsequent backup operations, the snapshot difference API might identify changed files with non 7-bit ASCII characters in their names, but reported the names incorrectly to the backup application. As a result, these files could not be processed by the backup application.

If the filer is later updated with a snapshot difference API that supports non 7-bit ASCII ("Unicode") characters, a one-time full backup may be needed to ensure that all file changes are properly captured after the update. Consider the following example:

1. A filer with a snapshot difference API that supports only 7-bit ASCII characters contains a file named FürElise.mp3. Note that the file name includes a 'u' with an umlaut, which is a non 7-bit ASCII character.

2. During the initial snapshot backup FürElise.mp3 is backed up.
3. After the initial backup, Für


Elise.mp3 is changed.
4. During the next snapshot backup the snapshot difference API identifies that Für

_Elise.mp3 has changed but reports the name incorrectly to the backup

_Elise.mp3 is not backed up.

5. The snapshot difference API is updated to a version that supports non 7-bit ASCII characters.

6. The next snapshot backup does not report Für

                               Elise.mp3 because it did not change since the prior backup. Subsequent snapshot backups will not back up the file unless it changes again. As a result there is no backup copy of the changed version of Für


_Elise.mp3. Hence the need for the one-time full backup

to ensure that all files are properly backed up.

One possible solution is for the backup application to force a full backup the first time it detects a version of the snapshot difference API that can support file names with non 7-bit ASCII characters. While this ensures maximum protection of the data, a full backup can run well beyond the normal backup window, impacting other operations in

application. This means that the new version of Für


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