OS Error 665(failed to retrieve text for this error. Reason: 15105) while performing backup

Hi everyone,

I am performing a backup of sharepoint 2010 content database on my sql 2008 std edition which has file stream enabled and I experience the following problem.

When the backup reaches 40% (both when I do it via SSMS or via Maintenance plan) I get the following error:

BackupIoRequest::ReportIoError: write failure on backup device 'K:\SQL Backup\SP_Content2010.bak'. Operating system error 665(failed to retrieve text for this error. Reason: 15105).
Error: 18210, Severity: 16, State: 1.

I also tried backup the database on a different disk to make sure the problem is not there, but the same error appeared when the backup reached 40 %. I also executed DBCC CHECKDB against the database but it run successfully.

I could not find any other relevant source what the problem might be.

Any help will be very much appreciated.

Thanks