SCSI Generic, QLA2342, transfer size limitations
 

Does anyone know how to find out the what the value for "max_scsi_adapter_scatter_gather_elements" is? I'm write some code that uses SG to send SCSI commands to a SCSI target and have experimentally found the following on Redhat 9.

Memory mapped IO can handle transfer sizes up to 640K.
Direct and Indirect IO can handle data transfers up to 1MB. The SG HOWTO says the following expression is the transfer size limit for Direct IO.

[(max_scsi_adapter_scatter_gather_elements - 1) * PAGE_SIZE]


Thanks,
Nate