On Tue, 2010-01-05 at 10:23 -0700, Yongjian Zhang wrote: > Hi all, > > I'm trying to use disktest to measure the performance of an iSCSI device but > get extremely low throughput... >
How about the following manpage inside LTP source: # man ./testcases/kernel/io/disktest/man1/disktest.1 Regards-- Subrata > For example, I did > > disktest -w -S0:1k -B 1024 /dev/sdb (/dev/sdb is the iSCSI device file, no > partition or file system on it) > > And the result was: > | 2010/01/05-02:58:26 | START | 27293 | v1.4.2 | /dev/sdb | Start > args: -w -S0:1024k -B 1024 -PA (-I b) (-N 8385867) (-K 4) (-c) (-p R) > (-L 1048577) (-D 0:100) (-t 0:2m) (-o 0) > | 2010/01/05-02:58:26 | INFO | 27293 | v1.4.2 | /dev/sdb | Starting > pass > ^C| 2010/01/05-03:00:58 | STAT | 27293 | v1.4.2 | /dev/sdb | Total > bytes written in 85578 transfers: 87631872 > | 2010/01/05-03:00:58 | STAT | 27293 | v1.4.2 | /dev/sdb | Total > write throughput: 701055.0B/s (0.67MB/s), IOPS 684.6/s. > | 2010/01/05-03:00:58 | STAT | 27293 | v1.4.2 | /dev/sdb | Total > Write Time: 125 seconds (0d0h2m5s) > | 2010/01/05-03:00:58 | STAT | 27293 | v1.4.2 | /dev/sdb | Total > overall runtime: 152 seconds (0d0h2m32s) > | 2010/01/05-03:00:58 | END | 27293 | v1.4.2 | /dev/sdb | User > Interrupt: Test Done (Passed) > > As you can see, the throughput was only 0.67MB/s and only 85578 > written in 87631872 transfers... > I also tweaked the options with "-p l" and/or "-I bd" (change seek > pattern to linear and/or speficy IO type as block and direct IO) but > no improvement happened... > > I thought this low throughput could be caused by the link rate or disk > problem, but dd ruled it out.. > > $ dd if=/dev/zero of=/dev/sdb bs=1024 count=1048576 > > The throughput is 7.2 MB/s. > > There must be something I've done wrong with disktest... Could anyone maybe > help me out here? > > Thanks a lot! > > jack > > > ------------------------------------------------------------------------------ > This SF.Net email is sponsored by the Verizon Developer Community > Take advantage of Verizon's best-in-class app development support > A streamlined, 14 day to market process makes app distribution fast and easy > Join now and get one step closer to millions of Verizon customers > http://p.sf.net/sfu/verizon-dev2dev > _______________________________________________ > Ltp-list mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/ltp-list ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Ltp-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ltp-list
