Bug 911990

Summary: RFE: Support 4k sector size with qcow2
Product: Red Hat Enterprise Linux 7 Reporter: Xu Tian <xutian>
Component: qemu-kvmAssignee: Kevin Wolf <kwolf>
Status: CLOSED DUPLICATE QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: high    
Version: 7.0CC: acathrow, areis, bili, crobinso, hhuang, huding, juzhang, kwolf, lsu, qiguo, qzhang, shyu, sluo, virt-maint, xfu, xwei, yinyin2010
Target Milestone: rcKeywords: FutureFeature
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-01-22 11:06:50 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:
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strace output none

Description Xu Tian 2013-02-17 05:21:35 UTC 
Description of problem:

start guest with command:
qemu-kvm -name vm1 -smp 1 -m 512 -drive file=/tmp/test1.img,if=none,id=drive-virtio-disk1,media=disk,cache=none -device virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1 -vnc :0 -monitor stdio
guest to startup and error printed, "qemu-kvm: -drive file=/tmp/test1.img,if=none,id=drive-virtio-disk1,media=disk,cache=none: could not open disk image /tmp/test1.img: Invalid argument"

when cache=unsafe,writethrough or writeback guest start up successful;

when change cache=o, qemu quit with invalid cache option(that we expect)


Version-Release number of selected component (if applicable):

qemu-kvm-1.3.0-5.el7.x86_64
kernel-3.7.0-0.34.el7.x86_64

How reproducible:

100%

Steps to Reproduce:
1. boot guest with command:
qemu-kvm -name vm1 -smp 1 -m 512 -drive file=/tmp/test1.img,if=none,id=drive-virtio-disk1,media=disk,cache=none -device virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1 -vnc :0 -monitor stdio
(qemu quit,with error)

2. boot guest with command:
 qemu-kvm -name vm1 -smp 1 -m 512 -drive file=/tmp/test1.img,if=none,id=drive-virtio-disk1,media=disk,cache=unsafe -device virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1 -vnc :0 -monitor stdio
QEMU 1.3.0 monitor - type 'help' for more information
(qemu) info block
drive-virtio-disk1: removable=0 io-status=ok file=/tmp/test1.img ro=0 drv=qcow2 encrypted=0 bps=0 bps_rd=0 bps_wr=0 iops=0 iops_rd=0 iops_wr=0
ide1-cd0: removable=1 locked=0 tray-open=0 io-status=ok [not inserted]
floppy0: removable=1 locked=0 tray-open=0 [not inserted]
sd0: removable=1 locked=0 tray-open=0 [not inserted]
pflash0: removable=0 file=/usr/share/qemu/bios.bin ro=1 drv=raw encrypted=0 bps=0 bps_rd=0 bps_wr=0 iops=0 iops_rd=0 iops_wr=0

  
Actual results:

qemu quit when cache=none

Expected results:

guest startup

Additional info:
Comment 2 juzhang 2013-02-17 07:18:07 UTC 
FYI

I tried this issue by using qemu-kvm-1.3.0-5.el7.x86_64. Do not hit this issue. The guest be booted with cache=none.

#/usr/libexec/qemu-kvm -M pc-1.3 -cpu SandyBridge -enable-kvm -m 2048 -smp 2,sockets=1,cores=2,threads=1 -name rhel7 -uuid 6afa5f93-2d4f-420f-81c6-e5fdddbd1c83 -drive file=/home/a.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,serial=40c061dd-5d60-4fc5-865f-55db700407f0,cache=none,werror=stop,rerror=stop,aio=threads -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0  -vnc :1 -monitor stdio
Comment 5 Hai Huang 2013-02-19 14:33:21 UTC 
Verified that problem did NOT exist in prior RHEL7 nightly builds (before 1/15/2013).

Email thread already started with Kevin, so assigning this BZ to Kevin for 
now.  Please re-assign as appropriate.
Comment 6 Kevin Wolf 2013-02-20 10:33:10 UTC 
Your image is /tmp/test1.img. What kind of file system is /tmp on? If it's tmpfs, this doesn't support O_DIRECT, so the error would be expected.
Comment 7 Xu Tian 2013-02-21 02:58:56 UTC 
(In reply to comment #6)
> Your image is /tmp/test1.img. What kind of file system is /tmp on? If it's
> tmpfs, this doesn't support O_DIRECT, so the error would be expected.

hi Kevin,

create image file via "qemu-img create -f qcow2 /root/test.img 1G" and try to start up guest with cache=none still failed;  file system on /root is xfs:

/dev/mapper/rhel-root / xfs rw,relatime,attr2,inode64,noquota 0 0

try "dd if=/dev/zero of=/root/test2.img oflag=direct bs=1 count=1" it failed too, it looks root cause is fail to open image file with "O_DIRECT" on xfs file system;


thanks,
Xu
Comment 8 Xu Tian 2013-02-21 03:07:08 UTC 
Since this defeat caused by fail to open file with O_DIRECT in XFS file-system, so move it file-system component and update bug title;

Thanks,
Xu
Comment 9 Xu Tian 2013-02-21 03:51:23 UTC 
(In reply to comment #7)
> (In reply to comment #6)
> > Your image is /tmp/test1.img. What kind of file system is /tmp on? If it's
> > tmpfs, this doesn't support O_DIRECT, so the error would be expected.
> 
> hi Kevin,
> 
> create image file via "qemu-img create -f qcow2 /root/test.img 1G" and try
> to start up guest with cache=none still failed;  file system on /root is xfs:
> 
> /dev/mapper/rhel-root / xfs rw,relatime,attr2,inode64,noquota 0 0
> 
> try "dd if=/dev/zero of=/root/test2.img oflag=direct bs=1 count=1" it failed
> too, it looks root cause is fail to open image file with "O_DIRECT" on xfs
> file system;
> 
> 
> thanks,
> Xu

sorry to used incorrect command in above comments, please ignore it;

used a incorrect dd command:"dd if=/dev/zero of=/root/test2.img oflag=direct bs=1 count=1", invalid value of bs; 

try with "dd if=/dev/zero of=/root/test2.img oflag=direct bs=1M count=1" dd works well;

thanks,
Xu
Comment 10 Xu Tian 2013-02-21 04:00:41 UTC 
test below case:

1: create qcow2 image via qemu-img:

result: guest not start up

[root@localhost ~]# qemu-img create -f qcow2 /root/test-qcow2.img  1G 
Formatting '/root/test-qcow2.img', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off 
[root@localhost ~]# qemu-img info /root/test-qcow2.img 
image: /root/test-qcow2.img
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 196K
cluster_size: 65536
[root@localhost ~]# qemu-kvm -drive file=/root/test-qcow2.img,if=none,cache=none,media=disk,format=qcow2 -vnc :0
qemu-kvm: -drive file=/root/test-qcow2.img,if=none,cache=none,media=disk,format=qcow2: could not open disk image /root/test-qcow2.img: Invalid argument

2: create raw image with "qemu-img" 

result: guest start up 

[root@localhost ~]# qemu-img create -f raw test-raw.img 1G
Formatting 'test-raw.img', fmt=raw size=1073741824 
[root@localhost ~]# qemu-kvm -drive file=/root/test-raw.img,if=none,cache=none,media=disk,format=raw -vnc :0

3. create raw image with "dd"

result: guest start up

[root@localhost ~]# dd if=/dev/zero of=/root/test-dd.img bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 0.345461 s, 3.1 GB/s
[root@localhost ~]# qemu-kvm -drive file=/root/test-dd.img,if=none,cache=none,media=disk,format=raw -vnc :0(In reply to comment #8)
> Since this defeat caused by fail to open file with O_DIRECT in XFS
> file-system, so move it file-system component and update bug title;
> 
> Thanks,
> Xu

test below case:

1: create qcow2 image via qemu-img:

result: guest not start up

[root@localhost ~]# qemu-img create -f qcow2 test-qcow2.img 1G
Formatting 'test-qcow2.img', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off

[root@localhost ~]# strace  -o /tmp/strace.log qemu-kvm -drive file=/root/test-qcow2.img,if=none,cache=none,media=disk,format=qcow2 -vnc :0
qemu-kvm: -drive file=/root/test-qcow2.img,if=none,cache=none,media=disk,format=qcow2: could not open disk image /root/test-qcow2.img: Invalid argument

[root@localhost ~]# qemu-img info /root/test-qcow2.img
image: /root/test-qcow2.img
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 196K
cluster_size: 65536
[root@localhost ~]# 


2: create raw image with "qemu-img" 

result: guest start up 

[root@localhost ~]# qemu-img create -f raw test-raw.img 1G
Formatting 'test-raw.img', fmt=raw size=1073741824 
[root@localhost ~]# qemu-kvm -drive file=/root/test-raw.img,if=none,cache=none,media=disk,format=raw -vnc :0

3. create raw image with "dd"

result: guest start up

[root@localhost ~]# dd if=/dev/zero of=/root/test-dd.img bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 0.345461 s, 3.1 GB/s
[root@localhost ~]# qemu-kvm -drive file=/root/test-dd.img,if=none,cache=none,media=disk,format=raw -vnc :0

Base on above test result, move back this bug to qemu-kvm component;
Comment 11 Xu Tian 2013-02-21 04:02:44 UTC 
Created attachment 700331 [details]
strace output
Comment 12 Xu Tian 2013-02-21 04:09:13 UTC 
Hi Kevin,

qemu-img version is "qemu-img-1.3.0-5.el7.x86_64", and I have post strace output; do you have suggestion? Anything need me to try, please ping me when free.

thanks,
Xu
Comment 13 Kevin Wolf 2013-02-21 09:23:36 UTC 
Please use -f with strace, the main thread of qemu doesn't do anything interesting.

Does dd oflag=direct work with a block size of 512?
Comment 14 Xu Tian 2013-02-21 10:55:58 UTC 
(In reply to comment #13)
> Please use -f with strace, the main thread of qemu doesn't do anything
> interesting.
> 
> Does dd oflag=direct work with a block size of 512?

Hi Kevin,

"dd if=/dev/zero of=/root/test.img  oflag=direct  bs=512b" works fine, but bs=1k not work, see details below:

[root@localhost ~]# dd if=/dev/zero of=/root/test.img  oflag=direct  bs=512b count=100
100+0 records in
100+0 records out
26214400 bytes (26 MB) copied, 0.361657 s, 72.5 MB/s

[root@localhost ~]# dd if=/dev/zero of=/root/test.img  oflag=direct  bs=1k count=100
dd: writing ‘/root/test.img’: Invalid argument
1+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000215752 s, 0.0 kB/s
[root@localhost ~]# dd if=/dev/zero of=/root/test.img  oflag=direct  bs=4k count=1024
1024+0 records in
1024+0 records out
4194304 bytes (4.2 MB) copied, 0.277361 s, 15.1 MB/s
[root@localhost ~]# dd if=/dev/zero of=/root/test.img  oflag=direct  bs=4k count=10240
10240+0 records in
10240+0 records out
41943040 bytes (42 MB) copied, 1.22037 s, 34.4 MB/s

[root@localhost ~]# uname -a
Linux localhost.localdomain 3.7.0-0.34.el7.x86_64 #1 SMP Thu Jan 31 13:59:22 EST 2013 x86_64 x86_64 x86_64 GNU/Linux

thanks,
Xu
Comment 15 Xu Tian 2013-02-21 12:21:58 UTC 
Re-test this defeat with below scenerios:

boot guest with 4k virtual block size + raw image:

guest start up

[root@localhost ~]#  /usr/libexec/qemu-kvm -drive file=/root/test.raw,if=none,cache=none,format=raw,media=disk,id=drive-virtio-disk1 -device virtio-blk-pci,drive=drive-virtio-disk1,id=virtio-disk1,physical_block_size=4096  -smp 1 -m 512 -vnc :0

boot guest boot guest with 4k virtual block size + qcow2 image:

fail to start up guest

[root@localhost ~]#  /usr/libexec/qemu-kvm -drive file=/root/test.qcow2,if=none,cache=none,format=qcow2,media=disk,id=drive-virtio-disk1 -device virtio-blk-pci,drive=drive-virtio-disk1,id=virtio-disk1,physical_block_size=4096  -smp 1 -m 512 -vnc :0
qemu-kvm: -drive file=/root/test.qcow2,if=none,cache=none,format=qcow2,media=disk,id=drive-virtio-disk1: could not open disk image /root/test.qcow2: Invalid argument


Thanks for Kevin Wolf help on re-test this defeat;

Xu
Comment 16 Xu Tian 2013-02-26 08:12:37 UTC 
(In reply to comment #15)
> Re-test this defeat with below scenerios:
> 
> boot guest with 4k virtual block size + raw image:
> 
> guest start up
> 
> [root@localhost ~]#  /usr/libexec/qemu-kvm -drive
> file=/root/test.raw,if=none,cache=none,format=raw,media=disk,id=drive-virtio-
> disk1 -device
> virtio-blk-pci,drive=drive-virtio-disk1,id=virtio-disk1,
> physical_block_size=4096  -smp 1 -m 512 -vnc :0
> 
> boot guest boot guest with 4k virtual block size + qcow2 image:
> 
> fail to start up guest
> 
> [root@localhost ~]#  /usr/libexec/qemu-kvm -drive
> file=/root/test.qcow2,if=none,cache=none,format=qcow2,media=disk,id=drive-
> virtio-disk1 -device
> virtio-blk-pci,drive=drive-virtio-disk1,id=virtio-disk1,
> physical_block_size=4096  -smp 1 -m 512 -vnc :0
> qemu-kvm: -drive
> file=/root/test.qcow2,if=none,cache=none,format=qcow2,media=disk,id=drive-
> virtio-disk1: could not open disk image /root/test.qcow2: Invalid argument
> 
> 
> Thanks for Kevin Wolf help on re-test this defeat;
> 
> Xu

My hard disk sector size:

Sector size (logical/physical): 512 bytes / 4096 bytes
Comment 17 Qian Guo 2013-10-11 04:47:37 UTC 
*** Bug 1018028 has been marked as a duplicate of this bug. ***
Comment 18 Ademar Reis 2013-12-06 12:17:25 UTC 
*** Bug 960803 has been marked as a duplicate of this bug. ***
Comment 19 Kevin Wolf 2014-01-22 11:06:50 UTC 

*** This bug has been marked as a duplicate of bug 748906 ***