On Fri, Oct 17, 2008 at 1:49 AM, Richard Sharpe <realrichardsharpe@xxxxxxxxx> wrote: > On Thu, Oct 16, 2008 at 1:53 AM, ronnie sahlberg > <ronniesahlberg@xxxxxxxxx> wrote: >> OFF TOPIC : >> >> On Wed, Oct 8, 2008 at 5:14 PM, FUJITA Tomonori >> <fujita.tomonori@xxxxxxxxxxxxx> wrote: >>> >>> My point is that the performance of read-world workload benchmark like >>> dbench are relevant for the users than the performances of sequential >>> accesses. >> >> >> Funny you should mention DBENCH ( http://dbench.samba.org ). >> I recently added a NFS backend so that dbench can generate raw NFS >> traffic using "nfs-style" loadfiles. With the ability to take a NFS >> network trace and convert into one such loadfile automatically. >> >> I also recently added a SCSI backend to dbench (though it only handles >> READ10 and TESTUNITREADY commands so far) with the intent of being >> able to trace from a kernel the set of all SCSI operations perfromed >> durign some operation and then use "dbench -B scsi" to replay the >> exact same set of commands. >> My vision is that this could then be used to compare different devices >> how they operate on specific kinds of workloads. >> Maybe one "loadfile" that records and replays all SCSI i/o that goes >> to a device while one is recompiling a kernel, while operating on a >> very large picture in GIMP, reading a very large document into >> openoffice, etc etc. > > Hmmm, it struck me recently that one could write a simple filter SCSI > LLD that interposes itself between a real LLD and the SCSI ML and > captures all CDBs and some of the data on the way through and makes it > available for a capture program in the same way as the packet capture > stuff works. > > In some ways, this would be more convenient than using iSCSI ... That would be incredibly useful. The best would probably be to build this support into libpcap, like how capturing a USB bus works. With a new DLT value for pcap for storing raw scsi frames and pseudoframes we would have a fileformat defined already and would very easily have instant support in many applications that already operate on sequences of frames. ronnie sahlberg -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
