Unable to append tape with MTWEOFI enabled

I’ve observed the following issue on Media Agents on Linux with MTWEOFI support turned on in omnirc (to optimize performance) when running recent versions of Data Protector such as A.09.09_116.

While the first write operation to a blank or expired media will succeed an append operation to a tape by the Linux Media Agent will generate the following error. The media in question will be marked as poor.

[Major] From: BMA@linux.syncer.de "MSL6480_D1" Time: 18.11.2017 01:56:54
[90:183]     Cannot backspace block. (Details unknown.)

[Major] From: BMA@linux.syncer.de "MSL6480_D1" Time: 18.11.2017 01:56:54
[90:65]     /dev/tape/by-id/scsi-350014380032e2efc-nst
    Cannot append to medium (Details unknown.)

An intermediate fix has been made available by Micro Focus support in QCCR2A77211_HF1 which includes an hot fix for the Linux BMA. This fix also requires to specify the following options while OB2EODMETHOD=1 was previously not required.

# Enable MTWEOFI support on Linux Media Agent / Performance

Updated Information for Data Protector 10.x

Unfortunately more recent Data Protector versions (A.10.00 to A.10.20) re-introduced the problem. A fix has been confirmed as working in the meantime. If you need this functionality please request hot fix QCCR2A81967_HF3 from software support.