>
> El 27/2/16 a les 0:47, Brandon Adkins ha escrit:
> >
> >
> >> Subject: Re: [Xen-users] Xen 4.4.1 on Debian Jessie: freeze using "xl
> > create" on second VM
> >> To: badkins79@xxxxxxx; xen-users@xxxxxxxxxxxxx
> >> From: roger.pau@xxxxxxxxxx
> >> Date: Fri, 26 Feb 2016 09:32:13 +0100
> >>
> >> El 26/2/16 a les 6:25, Brandon Adkins ha escrit:
> >> >
> >> >
> >> >>
> >> >> El 24/2/16 a les 18:13, Brandon Adkins ha escrit:
> >> >> > Hi Roger,
> >> >> > The log messages I entered before are for the second guest. I didn't
> >> > include any logs for the second guest since that one works perfectly.
> >> >> > But maybe I am allocating my RAM too tightly? The system has 16 GB
> >> > of RAM, or 16,384MB. I allocated 4096MB to the host. That leaves me with
> >> > 12,228MB. Each VM gets 6000, so thats 228MB unaccounted for. Is there
> >> > some minimum amount that needs to remain above that?
> >> >> > Looking at "xl info" with both guests started, it says my total
> >> > memory is 16,353, and that my free memory is 45.
> >> >> > I also just tried reducing the RAM for both guests down to 5500. I
> >> > got the same error when starting the second guest. Thats about 1 GB of
> >> > unallocated space, so I don't think thats my issue.
> >> >> > I also just tried stopping both guests, and starting guest1 first,
> >> > and guest0 second. Guest1 came up fine, and now guest0 is stuck. Its
> >> > definitely related to the second vm that starts, and not a specific
> >> > configuration.
> >> >> > I am really at a loss of where to look. Is there anything in the
> >> > config that would cause the CPUs to get assigned to the first guest, so
> >> > the second one is left with no CPUs?
> >> >> > Best,Beau
> >> >> >
> >> >>
> >> >> I don't see any error in the trace, AFAICT libxl has correctly created
> >> >> the domain. Can you paste the output of `xl list` after creating both
> >> >> guests?
> >> >>
> >> >> Roger.
> >> >
> >> > Hi Roger,
> >> >
> >> > Yes, I can't find any errors either, which makes debugging it almost
> >> > impossible for me. Here are some outputs:
> >> >>xl list
> >> > Name ID Mem VCPUs State
> >> > Time(s)
> >> > Domain-0 0 4087 2 r-----
> >> > 3308.0
> >> > guest1 132 5500 6 -b----
> >> > 533.0
> >> > guest0 133 5500 1 r-----
> >> > 130103.4
> >> >
> >> > Interesting to see the nonfunctional guest0 has such a high Time column.
> >> > Its like its spinning in a tight loop, while the working guest1 is
> >> > running fine. Note that this is the output of my last test setup, where
> >> > I gave both vms 5500MB of RAM, and tried starting guest1 first.
> >> >
> >> > xl vcpu-list
> >> > Name ID VCPU CPU State Time(s) CPU
> >> > Affinity
> >> > Domain-0 0 0 0 -b- 1554.4 0
> >> > Domain-0 0 1 1 r-- 1749.6 1
> >> > Domain-0 0 2 - --p 0.5 2
> >> > Domain-0 0 3 - --p 0.6 3
> >> > Domain-0 0 4 - --p 0.4 4
> >> > Domain-0 0 5 - --p 0.6 5
> >> > Domain-0 0 6 - --p 1.7 6
> >> > Domain-0 0 7 - --p 0.8 7
> >> > guest1 132 0 7 -b- 220.4 2-7
> >> > guest1 132 1 5 -b- 86.0 2-7
> >> > guest1 132 2 4 -b- 73.5 2-7
> >> > guest1 132 3 2 -b- 45.2 2-7
> >> > guest1 132 4 6 -b- 61.8 2-7
> >> > guest1 132 5 5 -b- 46.3 2-7
> >> > guest0 133 0 3 r-- 130279.1 2-7
> >> > guest0 133 1 - --p 0.0 2-7
> >> > guest0 133 2 - --p 0.0 2-7
> >> > guest0 133 3 - --p 0.0 2-7
> >> > guest0 133 4 - --p 0.0 2-7
> >> > guest0 133 5 - --p 0.0 2-7
> >> >
> >> > For some reason, even though I assigned 6 CPUs to both VMs, only the
> >> > first one started seems to get it right.
> >> >
> >> > I believe I must have some sort of screwed up Xen configuration. Surely
> >> > I am not the first person to try using Xen on Debian Jessie.
> >>
> >> Something seems wrong regarding guest0, but it looks like an issue in
> >> the guest kernel. Can you paste the output of xl dmesg after creating
> >> both guests?
> >>
> >> AFAICT from the traces you have provided, you are trying to create 32bit
> >> PV guests. Do they boot fine if you convert them to HVM? I would for
> >> example try to change the config files so they look like:
> >>
> >> guest0:
> >> builder='hvm'
> >> vcpus = '6'
> >> cpus = '2-7'
> >> memory = '6000'
> >> disk = [ 'phy:/dev/xenvolgroup/guest0disk,xvda2,w',
> >> 'phy:/dev/xenvolgroup/guest0swap,xvda1,w' ]
> >> name = 'guest0'
> >> vif = [ 'mac=AE:57:EC:01:54:8C,bridge=xenbr0' ]
> >> _on_poweroff_ = 'destroy'
> >> _on_reboot_ = 'restart'
> >> _on_crash_ = 'restart'
> >>
> >> vnc=1
> >> -----------------------------------------
> >> guest1:
> >> builder='hvm'
> >> vcpus = '6'
> >> cpus = '2-7'
> >> memory = '6000'
> >> disk = [ 'phy:/dev/xenvolgroup/guest1disk,xvda2,w',
> >> 'phy:/dev/xenvolgroup/guest1swap,xvda1,w' ]
> >> name = 'guest1'
> >> vif = [ 'mac=76:7B:D6:6F:34:C6,bridge=xenbr0' ]
> >> _on_poweroff_ = 'destroy'
> >> _on_reboot_ = 'restart'
> >> _on_crash_ = 'restart'
> >>
> >> vnc=1
> >> -----------------------------------------
> >>
> >> You can then attach to the guest display using a VNC client.
> >>
> >> Roger.
> >
> > Roger. This is a 64bit machine loaded with 64bit debian jessie. The
> > guest VMs are 32bit CentOS 6. However, both guest0 and guest1 are
> > identical. What could happen in the guest kernel that would allow one
> > instance to run just fine, but the second one to freeze on boot.
> >
> > I tried the "xl dmesg", but its difficult to tell what output in there
> > is related to what guest. But the end of the output contained lots of
> > the following 2 messages. Not sure if these mean anything:
> > (XEN) traps.c:2514:d132 Domain attempted WRMSR 0000000000000140 from
> > 0x0000000000000001 to 0x0000000000000000.
> > (XEN) event_fifo.c:50:d0 domain 0, port 19 already on a queue
> >
> > I tried using hvm to build the VMs, but that failed even on the first
> > VM. My output was:
> > Parsing config from /home/lpwcm/xen/guest0/guest.cfg
> > libxl: error: libxl_dm.c:1393:device_model_spawn_outcome: domain 138
> > device model: spawn failed (rc=-3)
> > libxl: error: libxl_create.c:1186:domcreate_devmodel_started: device
> > model did not start: -3
> > libxl: error: libxl_dm.c:1497:kill_device_model: Device Model already exited
>
> Can you check the logs in /var/log/xen/? You should see some logs with
> the following nomenclature "qemu-dm-<guest_name>.log"? Are there any
> errors reported there?
>
> Also, can you try again but with a higher debug value (using xl -vvv
> create ...) and post the result?
>
> Roger.
>
I have learned a bit more about this.
First, putting /boot on its own partition does not affect this issue.
Second, this issue happens both using lvm and loop disk images.
Third, I found out how to get the output of "xl dmesg" that corresponds to the failing domain. So when I attempt to create a VM that freezes, "xl dmesg" shows only this: "(XEN) event_fifo.c:50:d0 domain 0, port 19 already on a queue".
Does this mean anything to anyone? Has anyone been able to successfully start 2 Xen PV VMs on Debian Jessie?
Best regards,
Beau
