Date: Mon, 4 Mar 2002 18:03:22 -0800 From: Carl Reisinger <cer@mirapoint.com> To: freebsd-scsi@FreeBSD.org Subject: Writing > 64KB records to SCSI Tape, FreeBSD 4.1 (?) Message-ID: <200203050202.AOD05455@mail.mirapoint.com>
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I would like to write records of 128KB to a SCSI tape device (DLT 7 or 8000, LTO). While MAXPHYS is 128KB, the code in kern_physio:physio will adjust the max size based on the value of dev->si_iosize_max. It my case it appears that this value is 0 (or < PAGE_SIZE), so physio will set si_iosize_max to DFLTPHYS which is defined to be 64KB. In any case DFLTPHYS is the limit I am hitting. This in turn will cause the 128KB write to be broken into two 64KB writes, which just doesn't work for me. The best solution, for me, would be a change to scsi_sa.c that will set si_iosize_max for the device. Can anyone help? NOTE: While most of the kernel is based on 4.1-STABLE, I believe the CAM subsystem and scsi_sa has been lifted from 4.3. (The behaviour is the same under 4.5) Thanks, Carl Reisinger To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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