Hi all,
I am running a embedded OS on Qemu-2.3.0. However I found that the I/O
performance was quite different for different CentOS release (CentOS 6.5 and
CentOS 7.0). The CentOS 6.5 uses linux-2.6.32 while the CentOS 7.0 uses
linux-3.10.0. The I/O throughput (write) of the former (CentOS 6.5) is about
ten times of that on the latter (CentOS 7.0). All configurations are the same
except the kernel version. And the command line is as following:
# qemu-kvm -m 2G -smp 4 -enable-kvm -hda guest.img ...
The I/O throughput of the host is almost the same for these two different
kernels, as tested by Iozone tool. Actually, I found that the IO throughput
degraded significantly since the 3.4 or later kernel version. I also tried
different qemu versions such as qemu-1.5.3, qemu-2.1.3 but got no improvements.
Hope someone can provide helps.
Yi
