CUCM SFTP backup issue workaround

Problem:
SFTP transfer fails from Call Manager to any SFTP software (Solarwinds SFTP, WS_FTP, etc.)
Error message includes:
"SFTP transfer failed during Backup. Either there is not enough disk space or network transfer failed due to interuption while transferring data to configured SFTP Server."
Solution:
1. Disk space is full, check drive space is available.
2. Cisco recommends to use Prime SFTP, any Linux SFTP application, or Titan SFTP server for Windows.
3. This problem appears to be SMB2 related, performing manual "dir /r" from the command prompt while browsed to this directory refreshes the bytes on disk and allows the backup to complete successfully.  This command could potentially be scripted to ensure the directory is refreshed every few minutes.
See below bug CSCul38509 from:
CUCM DRS backup fails with windows 7 and 2008
CSCul38509
Symptom:
CUCM 8.6.2 or 9.1(2) and later DRS backup may fail due to interoperability issues with Windows 7 or Windows 2008 based SFTP servers or any SFTP server which uses SMB2 to access disk storage.

Conditions:
This has been observed under Windows 7 and Windows 2008.

To check if you are affected please conduct the following steps during file upload to your Windows-based SFTP server:
a) open CMD and change your current folder to SFTP root directory
b) issue dir command to check what is the size of the file being uploaded
c) you are affected if the file size is 0, it is not increasing, and it gets updated as soon as you issue dir /R command

Workaround:
1. Use linux-based SFTP server
or
2. From SFTP server do not mount storage via SMB2

Sources:
https://community.cisco.com/t5/ip-telephony-and-phones/cucm-9-1-2-backup-issue/td-p/2649506
https://quickview.cloudapps.cisco.com/quickview/bug/CSCul38509
Additional troubleshooting:
http://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/117725-probsol-cucm-00.html
Experience the same issue? Leave a comment below on how you addressed or solved it.  Thanks!