Re: [Xen-users] Remus: network buffering problem

[Shriram Rajagopalan <rshriram@xxxxxxxxx>]

On Sat, Feb 19, 2011 at 9:14 PM, Wenda Ni <wonda.ni@xxxxxxxxx> wrote:
> Hi Shriram,
>
> Thank you so much for your advice.
>
> I have enabled IFB (Intermediate functional block) module. I have enabled
> Ingress, redirecting, mirroring, NET_SCH_PLUG, and Netfilter. I have moduled
> or enabled the rest of the selections under QoS and/or fair queueing. Now it
> give the following error.
>
> I cannot find the sch_queue module under QoS and/or fair queueing. I find a
> few previous discussions about the sch_queue module, but have not found a
> good solution. Could you help a bit further? I am using XEN 4.0.1 release
> pvops on Ubuntu 10.10 (2.6.32.27).
>
You only need either sch_plug or the sch_queue. not both.
 this issue has been fixed in the latest xen-unstable. But it still
lingers in 4.0.1. Here is what I suggest

option 1:
Go to tools/remus/kmod/
 Hack the Makefile. I mean, manually set the KERNELDIR,
 remove the "grep CONFIG_IMQ..".
 if you do a make now, you should be able to compile the sch_queue module
 and then a make install.
 Basically, fix the makefile and compile/install the sch_queue module

Option 2:
 (I suggest you avoid this). Look at device.py and qdisc.py from xen-unstable
and fix your local repo's version (from xen 4.0.1).

BTW, you are probably going to be raising the next issue - Disk
replication fails.
 This is a bad hack but probably saves u time, for the moment, in
4.0.1. Edit the device.py near
  if disk.uname.startswith("tap:remus..") to "tap2:remus"...
 Unfortunately, 4.0.1 decided that users should explicitly specify
tap2:... to use blktap2 driver,
which meant that using tap:aio leads to loading blktap1
driver(deprecated/doesnt work in pvops).
So, one would have to use tap2:aio (loads blktap2 driver), and thus
similarly tap2:remus:..
        - but the remus scripts werent fixed soon enough to reflect
this, in 4.0.1. :(

shriram
>
> modprobe -q sch_queue
>
> Traceback (most recent call last):
>   File "/usr/bin/remus", line 210, in <module>
>     run(cfg)
>   File "/usr/bin/remus", line 119, in run
>     bufs.append(BufferedNIC(vif))
>   File "/usr/local/lib/python2.6/dist-packages/xen/remus/device.py", line
> 275, in __init__
>     self.setup()
>   File "/usr/local/lib/python2.6/dist-packages/xen/remus/device.py", line
> 314, in setup
>     raise BufferedNICException('could not load sch_queue module')
> xen.remus.device.BufferedNICException: could not load sch_queue module
>
>
>
> On Sat, Feb 19, 2011 at 6:25 PM, Shriram Rajagopalan <rshriram@xxxxxxxxx>
> wrote:
>>
>> On 2011-02-18, at 7:04 PM, Wenda Ni <wonda.ni@xxxxxxxxx> wrote:
>>
>> Hi, Todd
>>
>> I realize what you mean. <330.gif> Hope Shriram can shed some light to us!
>>
>> On Fri, Feb 18, 2011 at 9:44 PM, Todd Deshane <todd.deshane@xxxxxxx>
>> wrote:
>>>
>>> Adding our new remus maintainer to the CC
>>>
>>> On Fri, Feb 18, 2011 at 6:24 AM, Wenda Ni <wonda.ni@xxxxxxxxx> wrote:
>>> > Hello,
>>> >
>>> > Many thanks to Simon for his trouble shooting on live migration. I have
>>> > now
>>> > started testing remus according to the remus link
>>> > http://nss.cs.ubc.ca/remus/doc.html
>>> >
>>> > 1) Remus in its simplest mode (--no-net option), without disk
>>> > replication or
>>> > network protection, is now working good.
>>> >
>>> > 2) When we add the network buffering protection (remove the --no-net
>>> > option), remus gives the error as follows:
>>> >
>>> > modprobe -q ifb
>>> >
>>> > modprobe -q imq
>>> >
>>
>> Have you installed the ifb module?
>> You have to enable it while configuring the dom0 kernel.
>>  Device Drivers-->network devices-->Intermediate Frame Buffer
>> You also need to enable a whole bunch of other things
>>  Networking ->QoS ->Ingress, actions, mirred, redirect, etc
>>   and Plug Queue (NET_SCH_PLUG).
>>
>> You are better off at the moment to just enable all or most of the stuff
>> under Netfilter and Qos as modules. Might make your task easier.
>>
>> Btw thanks for pointing this out. These should probably be enabled by the
>> kernel build scripts (buildconfigs/enable-xen-config ) or some such place.
>>
>> Shriram
>>>
>>> > Traceback (most recent call last):
>>> >   File "/usr/bin/remus", line 210, in <module>
>>> >     run(cfg)
>>> >   File "/usr/bin/remus", line 119, in run
>>> >     bufs.append(BufferedNIC(vif))
>>> >   File "/usr/local/lib/python2.6/dist-packages/xen/remus/device.py",
>>> > line
>>> > 272, in __init__
>>> >     self.pool = Netbufpool(selectnetbuf())
>>> >   File "/usr/local/lib/python2.6/dist-packages/xen/remus/device.py",
>>> > line
>>> > 174, in selectnetbuf
>>> >     raise BufferedNICException('no net buffer available')
>>> > xen.remus.device.BufferedNICException: no net buffer available
>>> > Exception AttributeError: "'BufferedNIC' object has no attribute
>>> > 'bufdev'"
>>> > in <bound method BufferedNIC.__del__ of <xen.remus.device.BufferedNIC
>>> > object
>>> > at 0xd9dd90>> ignored
>>> >
>>> > I googled, but find little useful info. Could anyone know my problem?
>>> >
>>> > --
>>> > Cheers,
>>> >
>>> > Wenda Ni, Ph.D.
>>> > Dept. of Computer Science and Engineering
>>> > State University of New York (SUNY) at Buffalo
>>> >
>>> > _______________________________________________
>>> > Xen-users mailing list
>>> > Xen-users@xxxxxxxxxxxxxxxxxxx
>>> > http://lists.xensource.com/xen-users
>>> >
>>
>>
>>
>> --
>> Cheers,
>>
>> Wenda Ni, Ph.D.
>> Dept. of Computer Science and Engineering
>> State University of New York (SUNY) at Buffalo
>>
>
>
>
> --
> Cheers,
>
> Wenda Ni, Ph.D.
> Dept. of Computer Science and Engineering
> State University of New York (SUNY) at Buffalo
>
>

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