On 10/22/20 6:48 PM, Marcel Juffermans wrote:
Hi there,
Since upgrading to openSUSE 15.2 (which includes libvirt 6.0.0) the virtual
guests don't get their RBD disks made available to them. On openSUSE 15.1 (which
includes libvirt 5.1.0) that worked fine. The XML is as follows:
<domain type='xen' id='7'>
<name>mytwotel-a</name>
<uuid>a56daa5d-c095-49d5-ae1b-00b38353614e</uuid>
<description>mytwotel-a</description>
<memory unit='KiB'>1048576</memory>
<currentMemory unit='KiB'>1048576</currentMemory>
<vcpu placement='static'>1</vcpu>
<cputune>
<vcpupin vcpu='0' cpuset='8-23'/>
</cputune>
<os>
<type arch='x86_64' machine='xenpv'>linux</type>
<kernel>/usr/lib/grub2/x86_64-xen/grub.xen</kernel>
</os>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
<disk type='network' device='disk'>
<driver name='qemu' type='raw' cache='writethrough'/>
<source protocol='rbd' name='guests/mytwotel-a'>
<auth username='libvirt'>
<secret type='ceph' uuid='3f88b59a-d85b-4b47-946d-a4c4cce3fec0'/>
</auth>
</source>
<backingStore/>
<target dev='xvda' bus='xen'/>
</disk>
<controller type='xenbus' index='0'/>
<interface type='bridge'>
<mac address='00:16:3e:a3:ba:9f'/>
<source bridge='br0'/>
<target dev='vif7.0'/>
</interface>
<console type='pty' tty='/dev/pts/0'>
<source path='/dev/pts/0'/>
<target type='xen' port='0'/>
</console>
<input type='mouse' bus='xen'/>
<input type='keyboard' bus='xen'/>
<memballoon model='xen'/>
</devices>
</domain>
The virtual guest starts, but then sits in the Grub 2 boot prompt because the
disk is not available. The qemu log shows:
qemu-system-i386: failed to create 'qdisk' device '51712': failed to create
drive: Could not open
'rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\;none':
No such file or directory
qemu-system-i386: failed to create 'qdisk' device '51712': failed to create
drive: Could not open
'rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\;none':
No such file or directory
qemu-system-i386: failed to create 'qdisk' device '51712': failed to create
drive: Could not open
'rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\;none':
No such file or directory
qemu-system-i386: failed to create 'qdisk' device '51712': failed to create
drive: Could not open
'rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\;none':
No such file or directory
...
I tried to strace libvirtd. The results are as follows:
On openSUSE 15.2 with libvirt 6.0.0 (not working), we see this:
1682 openat(AT_FDCWD,
"rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\\;none",
O_RDWR|O_CLOEXEC) = -1 ENOENT (No such file or directory)
1682 rt_sigprocmask(SIG_BLOCK, NULL, [BUS USR1 ALRM IO], 8) = 0
1682 mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f538aefd000
1682 mprotect(0x7f538aefd000, 4096, PROT_NONE <unfinished ...>
1682 <... mprotect resumed>) = 0
1682 rt_sigprocmask(SIG_SETMASK, [BUS USR1 ALRM IO], [BUS USR1 ALRM IO], 8) = 0
1682 rt_sigprocmask(SIG_BLOCK, NULL, [BUS USR1 ALRM IO], 8) = 0
1682 mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0
<unfinished ...>
1682 <... mmap resumed>) = 0x7f538adfc000
1682 mprotect(0x7f538adfc000, 4096, PROT_NONE <unfinished ...>
1682 <... mprotect resumed>) = 0
1682 rt_sigprocmask(SIG_SETMASK, [BUS USR1 ALRM IO], <unfinished ...>
1682 <... rt_sigprocmask resumed>[BUS USR1 ALRM IO], 8) = 0
1682 write(2, "qemu-system-i386: failed to crea"..., 232 <unfinished ...>
...
On the other hand, on openSUSE 15.1 with libvirt 5.1.0 (working), we see this:
16267 openat(AT_FDCWD,
"rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\\;none",
O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
16267
stat("rbd:guests/mytwotel-a:id=libvirt:key=AQCAUpBbrcaiFxAA1sztXPbkdW1L54i99oUpyA==:auth_supported=cephx\\;none",
0x7fff83e2e2b0) = -1 ENOENT (No such file or directory)
16267 access("/usr/lib64/qemu/block-rbd.so", F_OK) = 0
16267 stat("/usr/lib64/qemu/block-rbd.so", {st_mode=S_IFREG|0644, st_size=27448,
...}) = 0
16267 openat(AT_FDCWD, "/usr/lib64/qemu/block-rbd.so", O_RDONLY|O_CLOEXEC) = 60
16267 read(60, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0
&\0\0\0\0\0\0"..., 832) = 832
16267 fstat(60, {st_mode=S_IFREG|0644, st_size=27448, ...}) = 0
16267 mmap(NULL, 2122672, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 60, 0)
= 0x7f8e6030f000
16267 mprotect(0x7f8e60315000, 2093056, PROT_NONE) = 0
16267 mmap(0x7f8e60514000, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 60, 0x5000) = 0x7f8e60514000
16267 close(60) = 0
...
Note that the latter opens "/usr/lib64/qemu/block-rbd.so". That library *does*
exist on openSUSE 15.2 but it doesn't seem to be used.
It smells like a bug in the Leap 15.2 qemu package. Or perhaps in xen's libxl
library, which controls the qemu processes used by VMs. I'd suggest entering a
bug at bugzilla.opensuse.org.
I've tried to update libvirt to a newer version using the Open Build Service
repos, but then ran into so many conflicting versions that I gave up.
At this point I'm stuck. Does anyone have an idea I can try?
We might be able to eliminate libxl by comparing the interaction with qemu
between the working and non-working setups. E.g. enable debug in
/etc/libvirt/libvirtd.conf, restart libvirtd, start the offending VM, then look
in /var/log/libvirt/libxl/libxl-driver.log for the qemu command line created by
libxl and qmp commands sent to qemu. If libxl prepares qemu similarly between
the two, then the issue is likely in the qemu package.
Regards,
Jim
