Upgrade issue with pre-8.1 clients and 8.1 or later media servers
With the NetBackup 8.1 upgrade, the fingerprinting algorithm was upgraded from MD5 to SHA2 to provide improved protection against security vulnerabilities. NetBackup introduced two conversion methods to convert existing MD5 fingerprint data to SHA2: rolling conversion and inline conversion. Problems occur under the conditions shown:
Client is pre-8.1 NetBackup.
Client uses Client Direct, which performs deduplication at the client.
Client is backed up by a NetBackup 8.1 or later media server.
Under these conditions, the fingerprint conversion happens inline. As a result, backup performance is negatively effected and the CPU processing load on the media server increases. The media server has to rehash the MD5 information and create a SHA2 fingerprint.
To prevent this issue:
For pre-8.1 clients, change their backup to use media server deduplication (MSDP) with a media server that is at NetBackup 8.1 or later. This action avoids the backup performing the inline conversion.
Do not use Client Direct on pre-8.1 clients that are backed up by 8.1 and later media servers.