NetWorker: backups to CloudBoost are aborted by CONNECTION_DISCONNECTED error

NetWorker backups are configured to go to a CloudBoost device. The NetWorker Storage Node performing the write operation observes a CONNECTION_DISCONNECTED error:
The error appears on the save process at the storage node, but is the Storage Node nsrmmd daemon reports the following:

MM/DD/YYYY HH:mm:SS nsrmmd SYSTEM critical Unable to write to a file: CONNECTION_DISCONNECTED
MM/DD/YYYY HH:mm:SS nsrmmd SYSTEM error Cannot write to base/NW_DEVICE_NAME/##/##/LONG_SSID - errno No error.
MM/DD/YYYY HH:mm:SS nsrmmd SYSTEM critical Unable to write buffer to disk for ssid=SSID: Failed opening file / directory base/NW_DEVICE_NAME/##/##/LONG_SSID: Magfs SDK returned: CONNECTION_DISCONNECTED.
MM/DD/YYYY HH:mm:SS nsrmmd NSR warning Unable to close or sync file for ssid=SSID: Failed to get fd for ssid=SSID to sync/close file
MM/DD/YYYY HH:mm:SS nsrmmd SYSTEM critical Unable to remove SSID file 'base/NW_DEVICE_NAME/##/##/LONG_SSID' on device 'rd=storagenode:base/NW_DEVICE_NAME': Unable to stat save set file 'base/NW_DEVICE_NAME/##/##/LONG_SSID': Unable to retrieve the file statistics: CONNECTION_DISCONNECTED
MM/DD/YYYY HH:mm:SS nsrmmd NSR error MM/DD/YY HH:mm:SS nsrmmd #5: save set \\NAS_FILER\CIFS_SHARE$\~snapshot\backup.0 for client nw_client_NAS was aborted and removed from volume VOLUME_NAME
MM/DD/YYYY HH:mm:SS nsrsnmd SYSTEM notice nw_cbcl_disconnect: Mount handle is NULL.

Similar errors are found in the NetWorker server and storage node's daemon.raw:

• Linux: /nsr/logs/daemon.raw
• Windows (Default): C:\Program Files\EMC NetWorker\nsr\logs\daemon.raw
•  NetWorker: How to use nsr_render_log to render .raw log files

• The nsrmmd daemon on the storage node reaches the internal timeout for a write operation.
• This error is because the CloudBoost appliance has a high number of requests at the time the issue was observed, this added load caused the nsrmmd connection to timeout.

1. On the NetWorker storage node used for the CloudBoost devices, create a file called nsrcbconfig (no extension) in the following path:

• Linux: /nsr/debug
• Windows (default): C:\Program Files\EMC NetWorker\nsr\debug

2. Add the following contents to the file:

   curlConnectTimeout=40000
   nwTimeoutSecs=600
   echoInterval=15000

3. Save the file.
4. Restart NetWorker services on the NetWorker storage node:

• Linux: systemctl restart networker
• Windows (PowerShell): net stop nsrexecd /y ; net start nsrexecd
  • If the Windows NetWorker storage node is also the NetWorker server, run: net start nsrd
  • If the Windows NetWorker storage node is also the NetWorker Management Console (NMC) server, run: net start gstd

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