The following message displays in the event log when the ProxySG appliance boots:
2011-01-01 00:00:00-00:00UTC  "Failed to read private key for /legacy/cache_engine/persistent/replicated/volatile//config/v8/ssh/ssh_host_key"  0 300000:1   cm.cpp:4731

What does this message mean?

This message appears because the ProxySG appliance, by default, does not have an SSHv1 host key pair. You can ignore this message.
If you add SSHv1 Host Key Pair, this message will no longer appear in the event log.

To add an SSHv1 Host Key Pair:
1. Launch the ProxySG Management Console.
2. Select Configuration -> Authentication -> Console Access.
3. Select the SSH Host tab nd then click Create in the SSHv1 Host Key Pair section of the screen.