Laurent Vivier wrote: > Hi, > > I made some benchmarks with dbench on linux/KVM. > > IDE means I use an image disk with "-hda" > SCSI means I use an image disk with "-sda" > (see the patch I proposed on qemu list: > http://www.mail-archive.com/[EMAIL PROTECTED]/msg08679.html ) > > threads KVM-21 KVM-21 KVM-24 KVM-24 KVM-25 KVM-25 > IDE SCSI IDE SCSI IDE SCSI > > 1 215.272 94.8775 318.626 319.533 307.111 331.757 > 2 212.061 91.3193 313.217 315.163 314.577 323.715 > 4 197.586 81.7551 291.752 276.044 292.084 271.191 > 8 144.814 58.5725 188.819 198.995 168.273 165.564 > 16 111.505 66.3605 139.824 157.617 150.822 123.671 > 32 43.4109 15.7386 48.2109 50.4114 59.1074 69.5717 > 64 21.0567 8.3535 11.3457 19.9483 20.4877 24.5627 > > results are in MB/sec > > Conclusion: > > KVM-25 is really better than KVM-21 > in most cases, SCSI is better than IDE >
Were you using libposix-aio? If not, did you change the aio_init function in block-raw.c (assuming that you're using a raw disk). Otherwise, QEMU by default will limit the glibc aio library to a single thread so you won't see a lot of the benefits of SCSI emulation. Regards, Anthony Liguori > Cheers, > Laurent > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > ------------------------------------------------------------------------ > > _______________________________________________ > kvm-devel mailing list > kvm-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/kvm-devel > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
