I recently set up a machine running FreeBSD 8.2 and just tried running a Quantum SDLT drive on an Adaptec 2940W. Using a blocking factor of 50KB, with dump, tar or just dd, I seem to only be getting about 350KB/s. On a similar machine with a DLT drive I get at least 1200KB/s.
Any clues as to why the SDLT drive is getting such poor performance?
Any clues as to why the SDLT drive is getting such poor performance?
Code:
Jun 5 02:45:17 dnn kernel: sa0 at ahc0 bus 0 scbus2 target 6 lun 0
Jun 5 02:45:17 dnn kernel: sa0: <QUANTUM SDLT320 5D5D> Removable Sequential Access SCSI-2 device
Jun 5 02:45:17 dnn kernel: sa0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit)