On 03/28/2010 12:03 PM, Hao, Xudong wrote:
Avi Kivity wrote:
You need to fold the -hda parameter into -driver, so the whole command
line becomes
qemu-system-x86_64 -m 512 -smp 4 -net
nic,macaddr=00:16:3e:79:0c:db,model=rtl8139 -net
tap,script=/etc/kvm/qemu-ifup -drive
file=/share/ltp_guest.img,cache=writeback
-hda is deprecated, it forces cache=writethrough.
Okay, cache=writeback can improve 28% performance of diotest, it cost 135 seconds which cost 182 sconds with cache=writethrough.
But in the report of bug, there was 2.53 times downgrade performance than before, so maybe still need somewhere tuning.
Can you try creating the image with
qemu-img create -f qcow2 -o cluster_size=4096 guest.img <size>
That reduces the cluster size to 4096, maybe that helps diotest.
--
error compiling committee.c: too many arguments to function
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