/sys/block/sdX/device/queue_depth file is read-write with libsata, but is read-only with SCSI controllers (at least with the ones we have -- mostly aic7xxx or mptsas). Googling for "disable tcq" gives results about {dis,en}abling TCQ at boot time, and also mentions ipr (which we don't have). Is there an option to control TCQ at runtime? I'm doing a set of (pretty interesting) tests of various drives and their TCQ/NCQ implementations, everything's simple on SATA front but I can't test different TCQ modes with SCSI drives because I can't find a way control TCQ at runtime, and since those are production machines (I plug/unplug spare drives for testing, but have no spare machines), I can't reboot them often. Thanks. /mjt - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html