Network connectivity errors

Magnus Box uploads files to Magnus Box Network (or to a cloud storage provider) over the internet. Occasionally, you may see errors such as the following:

• Couldn't save data chunk:
• HTTP/1.x transport connection broken
• net/http: request canceled (Client.Timeout exceeded while awaiting headers)
• wsarecv
• wsasend
• An existing connection was forcibly closed by the remote host
• dial tcp: lookup [...]: no such host
• connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

Magnus Box retries the upload several times, but eventually gives up. After a failed data chunk upload, you may see several more messages of the form Couldn't save data chunk: context canceled while Magnus Box terminates the other upload threads.

Network errors have many possible causes:

• Customer's PC
• Customer's network
• Customer's ISP
• Internet-wide outages between customer's ISP and our network

To troubleshoot these issues, please check:

• Does the backup succeed if it is retried?
  • Many network errors are temporary and will only occur rarely. In addition, a repeated second backup job will often run faster because many of the existing data chunks have already been uploaded. (Any unused data chunks in the Storage Vault will be automatically cleaned up by the next retention pass.)
• Does the error message always happen at a certain time of day?
  • It may be possible to reschedule the backup to avoid times of heavy internet congestion.
• Are there any corresponding messages for around the same time in your Magnus Box Server logs?
  • This is important to determine the cause of some failures.
  • Some relevant Magnus Box Server log messages take the form Error saving upload stream or Blocking re-upload of preexisting file

Error "local error: tls: record overflow"

This message means the connection was corrupted on its way across the network, so Magnus Box closed it.

It can happen because of random network conditions, and retrying the backup usually fixes it.

If it keeps happening, something is interfering with packets on the network. Common causes:

• a failing network card (NIC)
• a bad NIC driver or driver setting
• failing RAM, on the device or on any router in between
• an outdated firewall or proxy doing incorrect SSL/TLS inspection

For the technical background, see the record_overflow alert in IETF RFC 5246.

Still stuck? Email support@magnusbox.com with the user name, the device name and the job log.