24 socket write failed netbackup windows

This problem is observed to occur when the backup for a Windows client host to a RHEL media server fills a tape. A retry or restart of the backup a few minutes later will be successful if it does not result in a second span media event. The bpbkar debug log shows a socket write failure.

Expected bytes: The bpbrm debug log shows that the child received a status 24 from bpbkar while waiting for bptm to mount the next tape to finish the backup. The bpbrm parent then terminated bptm. The bptm debug log confirms that it was waiting for the next media to mount when terminated by bpbrm.

It was not attempting to access the socket to bpbkar at that point and is unaware that the socket to the client host has reset. The network capture shows an unusual sequence of behavior with regard to window size and scaling when TCP negotiated the socket setup prior to the data transfer.

Testing shows that several different combinations of older network drivers HP and Broadcom in this case will result in an invalid window scaling negotiation and the resulting TCP behavior.

Many sites may not be aware that this situation is present due to NetBackup automatic retry of the failed backup job, which likely will not encounter a span media event.

However, the best solution is to install network driver versions that properly negotiate and implement TCP window scaling per RFC In the interim, successful backups can occur without failure and retry by adjusting the TCP tunables on either the client or media server hosts. This will increase the amount of time allowed for new media to mount and position from 10 to seconds.

Great care should be exercised when modifying the registry! Product s : NetBackup. A Windows OS error is reported to the backup process due to the failure of the client network layer to send the backup data across the established link to the receiving server Error Message Client bpbkar logs: Review the list of entries containing the word 'offload'.

Disable all 'offload' settings. Netbackup 7 running on Windows R2 platform may encounter slow performance. Backup fails intermittently with status code socket write failed. Was this content helpful? Yes No Rating submitted. Please provide additional feedback optional :. Cancel Submit. You are using Microsoft Internet Explorer! Saran Brar.

Post by Justin Piszcz Hi, Has anyone seen anything like this before? Using a 1 MiB buffer size on the media server and the client, only Windows hosts seem to have problems, no problems whatsoever with Linux clients.

Before switching over from 1GbE media servers to 1GbE media servers, there were no problems. So there were quite a few changes, although the only clients affected seem to be Windows. Any thoughts here?