Poor performance on 80i

[MJ Vraspir]

I recently switched from DLT IIIXT to DLTIV tapes. Throughput has degraded using tar. Is there a setting (or firmware) for larger capacity tapes? What does size=300 (feet) in /etc/default/archive do for configuration?
SCO 5.0.5 Surestore 80 G internal

[David Ruska]

I can't help you with you 'size=300' question, but I can give you some general suggestions.

First, the data rate is double with type IV media, so you may not be sending data fast enough for the drive to stream. The tape block size is a big factor here - the larger the better. For example, Fbackup should be configured for a block size of at least 32K (done by setting the blocksperrecord parameter in the fbackup_config file to 32 or higher). I'm not sure how you configure tape blocksize using tar.