read/write performance degredation in ubuntu/debian?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



I have run iozone on my  ubuntu 8.10 VM and it says:

                                                            random
random    bkwd  record  stride
              KB  reclen   write rewrite    read    reread    read
write    read rewrite    read   fwrite frewrite   fread  freread
            4096       4   17520   49143   112222    94284   87115
44566   94074  50770   90387    17054    44816  104415    88611

... and that is unbearably slow. My  debian etch VM is somewhat better:

                                                           random
random    bkwd  record  stride
              KB  reclen   write rewrite    read    reread    read
write    read rewrite    read   fwrite frewrite   fread  freread
            4096       4   29559   80552   142286   144129  109956
73759  122737   86741  114894    28001    68013  128927   131687

..but viewing still very slow by a factor of 20, compared to my rPath
(a redhat-derived distro) 1.07 VM:

                                                            random
random    bkwd  record  stride
              KB  reclen   write rewrite    read    reread    read
write    read rewrite    read   fwrite frewrite   fread  freread
            4096       4  475392  724942  1043308  1080466 1012386
768492  970375 1683570  972908   447357   693303  993935  1059245

Maybe in debian/ubuntu there is some kernel setting related to disk
I/O that I need to tweak? Anyone else seen this problem before?
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux