Network Problem after update 3.0 -> 3.1: blkback

[kadafax]

Hello,

I have a big problem:
Dom0 is centos5.1, domU are centos5.1. My setup is really simple, the 
only thing is that I give 3 nics to the domU so I use a modified network 
script (which has worked since january... since fedora 6):
"
#!/bin/sh
dir=$(dirname "$0")
"$dir/network-bridge" "$@" vifnum=0
"$dir/network-bridge" "$@" vifnum=1
"$dir/network-bridge" "$@" vifnum=2
"

So I have updated my xen dom0 from 3.0.3-rc5-8.1.15.el5 to 
3.1.0-53.1.4.el5 (and kernel-xen 2.6.18-8.1.15.el5xen to 
2.6.18-53.1.4.el5xen) and now my domU cant access the network. The 
interfaces are good in the domU, all seems to be ok but there are no 
connectivity at all (no arp entries). This message shows up on the dom0 
each time I launch a domU:

blkback: ring-ref 9, event-channel 7, protocol 1 (x86_64-abi)

Do someone know what is happening ? this is very embarrassing after a 
simple upgrade... Hopefully I have another identical server (Centos 5.0 
with 5.1 domUs) which is still in 3.0 but I cant stay not updated.

Thanks for any help.

xm info:
host                   : host.foo.com
release                : 2.6.18-53.1.4.el5xen
version                : #1 SMP Fri Nov 30 01:21:23 EST 2007
machine                : x86_64
nr_cpus                : 4
nr_nodes               : 1
sockets_per_node       : 2
cores_per_socket       : 1
threads_per_core       : 2
cpu_mhz                : 2992
hw_caps                : bfebfbff:20100800:00000000:00000180:0000641d
total_memory           : 4095
free_memory            : 3246
xen_major              : 3
xen_minor              : 1
xen_extra              : .0-53.1.4.el5
xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p
xen_pagesize           : 4096
platform_params        : virt_start=0xffff800000000000
xen_changeset          : unavailable
cc_compiler            : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
cc_compile_by          : mockbuild
cc_compile_domain      :
cc_compile_date        : Fri Nov 30 00:37:12 EST 2007
xend_config_format     : 2

[Dustin Henning]

	Since you are running Xen, I assume you are booting to
2.6.18-53.1.4.el5xen and not 3.1.0-53.1.4.el5.  That said, have you tried
booting to 2.6.18-8.1.15.el5xen (presumably still on the machine) to see if
your VMs work then?  If they don't, then some other package upgraded
alongside the 3.1 kernel might be to blame, and I have certainly had
problems going from CentOS X.Y to CentOS X.Z in the past (not Xen problems,
but still).  Since you will presumably still want to go to the newer kernel
eventually, hopefully someone with more Xen/Linux experience can help you
troubleshoot the actual problem, but if booting to a previous kernel makes
you functional in the meantime, that certainly can't hurt.  Another thought,
assuming paravirt, is that you might need to change the kernel in your
config to the new version of the DomU kernel for compatibility or something,
but I don't know how likely that is to help with the problem.
	Dustin

-----Original Message-----
From: fedora-xen-bounces(a)redhat.com [mailto:[e-mail]]
On Behalf Of kfx
Sent: Monday, December 10, 2007 18:33
To: xen-users(a)lists.xensource.com; fedora-xen(a)redhat.com
Subject: [Fedora-xen] Network Problem after update 3.0 -> 3.1: blkback

Hello,

I have a big problem:
Dom0 is centos5.1, domU are centos5.1. My setup is really simple, the 
only thing is that I give 3 nics to the domU so I use a modified network 
script (which has worked since january... since fedora 6):
"
#!/bin/sh
dir=$(dirname "$0")
"$dir/network-bridge" "$@" vifnum=0
"$dir/network-bridge" "$@" vifnum=1
"$dir/network-bridge" "$@" vifnum=2
"

So I have updated my xen dom0 from 3.0.3-rc5-8.1.15.el5 to 
3.1.0-53.1.4.el5 (and kernel-xen 2.6.18-8.1.15.el5xen to 
2.6.18-53.1.4.el5xen) and now my domU cant access the network. The 
interfaces are good in the domU, all seems to be ok but there are no 
connectivity at all (no arp entries). This message shows up on the dom0 
each time I launch a domU:

blkback: ring-ref 9, event-channel 7, protocol 1 (x86_64-abi)

Do someone know what is happening ? this is very embarrassing after a 
simple upgrade... Hopefully I have another identical server (Centos 5.0 
with 5.1 domUs) which is still in 3.0 but I cant stay not updated.

Thanks for any help.

xm info:
host                   : host.foo.com
release                : 2.6.18-53.1.4.el5xen
version                : #1 SMP Fri Nov 30 01:21:23 EST 2007
machine                : x86_64
nr_cpus                : 4
nr_nodes               : 1
sockets_per_node       : 2
cores_per_socket       : 1
threads_per_core       : 2
cpu_mhz                : 2992
hw_caps                : bfebfbff:20100800:00000000:00000180:0000641d
total_memory           : 4095
free_memory            : 3246
xen_major              : 3
xen_minor              : 1
xen_extra              : .0-53.1.4.el5
xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p
xen_pagesize           : 4096
platform_params        : virt_start=0xffff800000000000
xen_changeset          : unavailable
cc_compiler            : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
cc_compile_by          : mockbuild
cc_compile_domain      :
cc_compile_date        : Fri Nov 30 00:37:12 EST 2007
xend_config_format     : 2


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[SOLVED] Network Problem after update 3.0 -> 3.1: blkback

[kadafax]

Thanks for your answer and sorry for top-posting. I've solved the problem:


Before in xen 3.0 this was okay:
vif = [ 'mac=aa:dd:rr:ee:ss:11', 'mac=aa:dd:rr:ee:ss:22, bridge=xenbr1']

The first vif was implicitly attached to bridge 0 (xenbr0). BUT now in
3.1 this doesn't work anymore, you must explicitly give the
"bridge=xenbr0" argument:
vif = [ 'mac=aa:dd:rr:ee:ss:11, bridge=xenbr0', 'mac=aa:dd:rr:ee:ss:22,
bridge=xenbr1']


Dustin Henning wrote:
>  	Since you are running Xen, I assume you are booting to
>  2.6.18-53.1.4.el5xen and not 3.1.0-53.1.4.el5.  That said, have you tried
>  booting to 2.6.18-8.1.15.el5xen (presumably still on the machine) to see if
>  your VMs work then?  If they don't, then some other package upgraded
>  alongside the 3.1 kernel might be to blame, and I have certainly had
>  problems going from CentOS X.Y to CentOS X.Z in the past (not Xen problems,
>  but still).  Since you will presumably still want to go to the newer kernel
>  eventually, hopefully someone with more Xen/Linux experience can help you
>  troubleshoot the actual problem, but if booting to a previous kernel makes
>  you functional in the meantime, that certainly can't hurt.  Another thought,
>  assuming paravirt, is that you might need to change the kernel in your
>  config to the new version of the DomU kernel for compatibility or something,
>  but I don't know how likely that is to help with the problem.
>  	Dustin
>
>  -----Original Message-----
>  From: fedora-xen-bounces(a)redhat.com [mailto:[e-mail]]
>  On Behalf Of kfx
>  Sent: Monday, December 10, 2007 18:33
>  To: xen-users(a)lists.xensource.com; fedora-xen(a)redhat.com
>  Subject: [Fedora-xen] Network Problem after update 3.0 -> 3.1: blkback
>
>  Hello,
>
>  I have a big problem:
>  Dom0 is centos5.1, domU are centos5.1. My setup is really simple, the 
>  only thing is that I give 3 nics to the domU so I use a modified network 
>  script (which has worked since january... since fedora 6):
>  "
>  #!/bin/sh
>  dir=$(dirname "$0")
>  "$dir/network-bridge" "$@" vifnum=0
>  "$dir/network-bridge" "$@" vifnum=1
>  "$dir/network-bridge" "$@" vifnum=2
>  "
>
>  So I have updated my xen dom0 from 3.0.3-rc5-8.1.15.el5 to 
>  3.1.0-53.1.4.el5 (and kernel-xen 2.6.18-8.1.15.el5xen to 
>  2.6.18-53.1.4.el5xen) and now my domU cant access the network. The 
>  interfaces are good in the domU, all seems to be ok but there are no 
>  connectivity at all (no arp entries). This message shows up on the dom0 
>  each time I launch a domU:
>
>  blkback: ring-ref 9, event-channel 7, protocol 1 (x86_64-abi)
>
>  Do someone know what is happening ? this is very embarrassing after a 
>  simple upgrade... Hopefully I have another identical server (Centos 5.0 
>  with 5.1 domUs) which is still in 3.0 but I cant stay not updated.
>
>  Thanks for any help.
>
>  xm info:
>  host                   : host.foo.com
>  release                : 2.6.18-53.1.4.el5xen
>  version                : #1 SMP Fri Nov 30 01:21:23 EST 2007
>  machine                : x86_64
>  nr_cpus                : 4
>  nr_nodes               : 1
>  sockets_per_node       : 2
>  cores_per_socket       : 1
>  threads_per_core       : 2
>  cpu_mhz                : 2992
>  hw_caps                : bfebfbff:20100800:00000000:00000180:0000641d
>  total_memory           : 4095
>  free_memory            : 3246
>  xen_major              : 3
>  xen_minor              : 1
>  xen_extra              : .0-53.1.4.el5
>  xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p
>  xen_pagesize           : 4096
>  platform_params        : virt_start=0xffff800000000000
>  xen_changeset          : unavailable
>  cc_compiler            : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
>  cc_compile_by          : mockbuild
>  cc_compile_domain      :
>  cc_compile_date        : Fri Nov 30 00:37:12 EST 2007
>  xend_config_format     : 2
>
>
>  --
>  Fedora-xen mailing list
>  Fedora-xen(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-xen
>
>
>

[Mark Nielsen]

there were some changes in how networking is done going from 5.0 to 5.1. 
You may need to revisit the documentation for CentOS 5.1

kfx wrote:
>  Hello,
>
>  I have a big problem:
>  Dom0 is centos5.1, domU are centos5.1. My setup is really simple, the 
>  only thing is that I give 3 nics to the domU so I use a modified 
>  network script (which has worked since january... since fedora 6):
>  "
>  #!/bin/sh
>  dir=$(dirname "$0")
>  "$dir/network-bridge" "$@" vifnum=0
>  "$dir/network-bridge" "$@" vifnum=1
>  "$dir/network-bridge" "$@" vifnum=2
>  "
>
>  So I have updated my xen dom0 from 3.0.3-rc5-8.1.15.el5 to 
>  3.1.0-53.1.4.el5 (and kernel-xen 2.6.18-8.1.15.el5xen to 
>  2.6.18-53.1.4.el5xen) and now my domU cant access the network. The 
>  interfaces are good in the domU, all seems to be ok but there are no 
>  connectivity at all (no arp entries). This message shows up on the 
>  dom0 each time I launch a domU:
>
>  blkback: ring-ref 9, event-channel 7, protocol 1 (x86_64-abi)
>
>  Do someone know what is happening ? this is very embarrassing after a 
>  simple upgrade... Hopefully I have another identical server (Centos 
>  5.0 with 5.1 domUs) which is still in 3.0 but I cant stay not updated.
>
>  Thanks for any help.
>
>  xm info:
>  host                   : host.foo.com
>  release                : 2.6.18-53.1.4.el5xen
>  version                : #1 SMP Fri Nov 30 01:21:23 EST 2007
>  machine                : x86_64
>  nr_cpus                : 4
>  nr_nodes               : 1
>  sockets_per_node       : 2
>  cores_per_socket       : 1
>  threads_per_core       : 2
>  cpu_mhz                : 2992
>  hw_caps                : bfebfbff:20100800:00000000:00000180:0000641d
>  total_memory           : 4095
>  free_memory            : 3246
>  xen_major              : 3
>  xen_minor              : 1
>  xen_extra              : .0-53.1.4.el5
>  xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p
>  xen_pagesize           : 4096
>  platform_params        : virt_start=0xffff800000000000
>  xen_changeset          : unavailable
>  cc_compiler            : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
>  cc_compile_by          : mockbuild
>  cc_compile_domain      :
>  cc_compile_date        : Fri Nov 30 00:37:12 EST 2007
>  xend_config_format     : 2
>
>
>  -- 
>  Fedora-xen mailing list
>  Fedora-xen(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-xen