Bug 1002493

Summary:	qemu-img convert rate about 100k/second from qcow2/raw to vmdk format on nfs system file
Product:	Red Hat Enterprise Linux 7	Reporter:	FuXiangChun <xfu>
Component:	qemu-kvm	Assignee:	Fam Zheng <famz>
Status:	CLOSED ERRATA	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	low	Docs Contact:
Priority:	low
Version:	7.0	CC:	hhuang, juzhang, michen, mrezanin, qiguo, rbalakri, sluo, tlavigne, virt-maint, wquan, xigao, xuhan
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	qemu-kvm-1.5.3-84.el7	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	1132385 (view as bug list)		Environment:
Last Closed:	2015-03-05 08:01:26 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:
Bug Depends On:
Bug Blocks:	1132385, 1171560

Description FuXiangChun 2013-08-29 10:24:02 UTC

Description of problem:
convert qcow2/raw to vmdk with qemu-img on nfs file system, and save objective file to nfs file system.  it　write speed only 100k/second. Use the same method to convert other format image, conver rate is normal. e.g
vmdk--->qcow2
vmdk--->raw
 

Version-Release number of selected component (if applicable):
qemu-kvm-1.5.2-3.el7.x86_64
3.10.0-11.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.mount nfs file system to local /mnt

2.time qemu-img convert -p -f qcow2 /mnt/rhel6.qcow2-O vmdk /mnt/rhel6-qcow2-vmdk
3.

Actual results:
convert rate only about 100k/sec

Expected results:
~40M

Additional info:
If objective file don't save on nfs file system, convert rate is good.

Comment 2 Fam Zheng 2014-04-18 12:44:40 UTC

Posted a patch to upstream:

http://patchwork.ozlabs.org/patch/340295/

Comment 8 Jeff Nelson 2014-12-16 23:40:31 UTC

Fix included in qemu-kvm-1.5.3-84.el7

Comment 10 Qian Guo 2014-12-23 07:42:21 UTC

Reproduced this bug with qemu-kvm-1.5.3-83.el7.x86_64

Steps:
1.Prepare a 3.2G actually size qcow2 image which is in nfs server.
# qemu-img info /mnt/rhel7/rhel7base.qcow2 
image: /mnt/rhel7/rhel7base.qcow2
file format: qcow2
virtual size: 30G (32212254720 bytes)
disk size: 3.2G
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false


2.Try to convert it to be vmdk format.
# time qemu-img convert -p -f qcow2 /mnt/rhel7/rhel7base.qcow2 -O vmdk /mnt/test2.vmdk


Result:
# time qemu-img convert -p -f qcow2 /mnt/rhel7/rhel7base.qcow2 -O vmdk /mnt/test2.vmdk
    (100.00/100%)

real	79m0.067s
user	0m4.741s
sys	0m26.629s


The speed is 675k/s, so this bug is reproduced.

Verified this bug with qemu-kvm-1.5.3-84.el7.x86_64 and qemu-kvm-rhev-2.1.2-17.el7.x86_64

Steps as above

Results:
1.With qemu-kvm-1.5.3-84.el7.x86_64

# time qemu-img convert -p -f qcow2 /mnt/rhel7/rhel7base.qcow2 -O vmdk /mnt/test1.vmdk
    (100.00/100%)

real	1m46.145s
user	0m3.416s
sys	0m15.311s

The speed is 32M/s

2.With qemu-kvm-rhev-2.1.2-17.el7.x86_64

#  time qemu-img convert -p -f qcow2 /mnt/rhel7/rhel7base.qcow2 -O vmdk /mnt/test2.vmdk
    (0.00/100%)
    (100.00/100%)

real	1m29.221s
user	0m2.212s
sys	0m4.666s

The speed is 36M/s

The speed is acceptable, so this bug is fixed by qemu-kvm-rhev-2.1.2-17.el7.x86_64 and qemu-kvm-1.5.3-84.el7.x86_64

Comment 12 errata-xmlrpc 2015-03-05 08:01:26 UTC

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.

https://rhn.redhat.com/errata/RHSA-2015-0349.html