Bug 814617
| Summary: | NFS performance regression in large file sequential writes. | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Quan Wenli <wquan> | ||||
| Component: | qemu-kvm | Assignee: | Paolo Bonzini <pbonzini> | ||||
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | ||||
| Severity: | unspecified | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 6.3 | CC: | acathrow, asias, bsarathy, dyasny, juzhang, michen, minovotn, mkenneth, pbonzini, tburke, virt-maint | ||||
| Target Milestone: | rc | Keywords: | Regression | ||||
| Target Release: | --- | ||||||
| Hardware: | Unspecified | ||||||
| OS: | Unspecified | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.287.el6 | Doc Type: | Bug Fix | ||||
| Doc Text: |
No Documentation Needed
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Story Points: | --- | ||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2012-06-20 11:47:07 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Attachments: |
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Created attachment 578965 [details]
ffsb large_file_creates_256k_1.profile
Hi Wenli, thanks for the report. Can you please test the qemu version prior to bug #767606 fix? We'll need to decide which component/release introduced the regression. Please help us do the bisect; Why didn't you move #767606 back into assigned state if you're sure that's the source cause as noted in https://bugzilla.redhat.com/show_bug.cgi?id=767606#c11 (In reply to comment #3) > Hi Wenli, thanks for the report. > Can you please test the qemu version prior to bug #767606 fix? > We'll need to decide which component/release introduced the regression. Please > help us do the bisect; Since qemu version-237 which is prior to bug #767606 fix was deleted in brew,I rebuild qemu-kvm-237 packages in https://brewweb.devel.redhat.com/taskinfo?taskID=4326145. Do same test w/ switching qemu-kvm back to 237(keep same host/guest kernel), get about 49Mb/s in 256kb sequential writes on raw format, it is quite same with rhel6.2 result in comment #0. > > Why didn't you move #767606 back into assigned state if you're sure that's the > source cause as noted in https://bugzilla.redhat.com/show_bug.cgi?id=767606#c11 yes, I should move it back to assigned immediately rather then waiting for customer's reply. From Paolo's last update on bug 767606 (c#16): "Kernel bug reopened as bug 815265, moved QE tracker to bug 814617, using that one to post the revert." Verified it w 2.6.32-269.el6.x86_64 and qemu-kvm-0.12.1.2-2.287.el6 by using same steps in comment #0. The result of FFSB on large file sequential writes(256k) is 46.9 Mb/s , there is no regression compared with rhel6.2host. Base on it,change it to verified.
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No Documentation Needed
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2012-0746.html |
Description of problem: Do kvm block regresson test w/ (1Gb link) nfs backend between rhel6.2GA and rhel6.3 beta1 hosts .there is 35% performance regression in large file sequential writes. Detailed result: ================================================================ raw format in LargeFile Creates(256KB) w/kernel-257 guest threads| IOPS| Thro(MBps)| rhel6.2GA 1| 195.35| 48.8| r63 kernel-267 qemu-272 1| 126.29| 31.6| diff % | -35.4| -35.2| qcow2 format in LargeFile Creates(256KB) w/kernel-257 guest threads| IOPS| Thro(MBps)| rhel6.2GA 1| 199.77| 49.9| r63 kernel-267 qemu-272 1| 130.61| 32.7| diff % | -34.6| -34.5| ================================================================ Version-Release number of selected component (if applicable): (host)kernel-2.6_32-262 qemu-kvm-0.12.1.2-257 (guest)kernel-2.6_32-257 How reproducible: always Steps to Reproduce: 1.mount 1gb netapp server in client. cat /proc/mounts 192.168.0.113:/vol/s2wquan116171nfs /home/kvm_autotest_root/images nfs rw,sync,relatime,vers=3,rsize=65536,wsize=65536,namlen=255,acregmin=0,acregmax=0,acdirmin=0,acdirmax=0,hard,noac,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.0.113,mountvers=3,mountport=4046,mountproto=tcp,local_lock=none,addr=192.168.0.113 0 0 3. create 20G raw/qcow2 images. qemu-img create -f raw /home/kvm_autotest_root/images/storage2.raw 20G qemu-img create -f qcow2 /home/kvm_autotest_root/images/storage2.qcow2 110G -o preallocation=metadata 4.Pass this raw/qcow2 file image to the KVM guest as a block device and use cache=none aio=threads for the KVM guest. /usr/libexec/qemu-kvm -name vm1 -nodefaults -vga std -chardev socket,id=qmp_monitor_id_qmpmonitor1,path=/tmp/monitor-qmpmonitor1-20120418-021037-GUK9,server,nowait -mon chardev=qmp_monitor_id_qmpmonitor1,mode=control -chardev socket,id=serial_id_20120418-021037-GUK9,path=/tmp/serial-20120418-021037-GUK9,server,nowait -device isa-serial,chardev=serial_id_20120418-021037-GUK9 -device ich9-usb-uhci1,id=usb1,bus=pci.0,addr=0x4 -drive file=/usr/local/autotest/tests/kvm/images/RHEL-Server-6.3-64-virtio.raw,index=0,if=none,id=drive-virtio-disk1,media=disk,cache=none,boot=off,snapshot=off,readonly=off,format=raw,aio=threads -device virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1 -drive file=/usr/local/autotest/tests/kvm/images/test.raw,index=2,if=none,id=drive-virtio-disk2,media=disk,cache=none,boot=off,snapshot=off,readonly=off,format=raw,aio=threads -device virtio-blk-pci,bus=pci.0,addr=0x6,drive=drive-virtio-disk2,id=virtio-disk2 -device virtio-net-pci,netdev=idExu1N2,mac=9a:ff:15:58:09:ce,id=ndev00idExu1N2,bus=pci.0,addr=0x3 -netdev tap,id=idExu1N2,vhost=on -m 4096 -smp 2,cores=1,threads=1,sockets=2 -cpu Westmere -device usb-tablet,id=usb-tablet1,bus=usb1.0 -vnc :1 -vga qxl -rtc base=utc,clock=host,driftfix=slew -M rhel6.3.0 -boot order=cdn,once=c,menu=off -no-kvm-pit-reinjection -enable-kvm 4)In the KVM guest (running RHEL6.3-257), write filed in second disk (dev/vdb). ,then format the virtual disk with ext4 and mount the virtual disk in the guest. mkfs.ext4 /dev/vdb; mount /dev/vdb /mnt 5)run ffsb test.define direct io is on in configuration of ffsb test # ffsb large_file_creates_256k_1.ffsb Actual results: Expected results: Additional info: this bug may caused by linearized QEMU hack removal patch in bug #767606.