here is what I found out today. This Error was reproducable on two
different machines, and I cannot think of the reason for the Problem,
maybe I should post it on some NFS list, thats what I'll try next, but
first I try here.
I use NFS to communicate data between dom0 and domU. I export some
folder in dom0 and mount that export as /home in domU
When I write data from domU into /home the system looses its Network
Connection (writing data from domU --> dom0).
Strangely that only happens with files bigger then 200kB. There is no
problem to write e.g. 50 kB into /home.
I can still login on xm console domU but after some moments the system
can only be shut down using xm destroy domU.
If I try to recreate domU i get the error:
Using config file "/home/vserver/springfield/start-springfield".
Error: Unable to connect to xend: Connection refused. Is xend running?
then I have to fully restart dom0. This happens every time.
I am using xen of fedora8 distribution with different clients but the
problem exists in both cases using a Fedora or gentoo domU.
I post version Info at the end of the mail.
I have tried a lot of things to get hold of what causes the problem:
In domU i tried to copy data from /home (mounted via NFS) into /root.
NO PROBLEM, the error only occurs on copying into /home
dom0(NFS server) <-- domU(NFS client) PROBLEM
dom0(NFS server) --> domU(NFS client) NO PROBLEM
I also tried it the other way round, but this caused no problem:
dom0(NFS client) <-- domU(NFS server) NO PROBLEM
dom0(NFS client) --> domU(NFS server) NO PROBLEM
I also tried to export and mount from localhost for domU and dom0, no
dom0(NFS client) <-- dom0(NFS server) NO PROBLEM
dom0(NFS client) --> dom0(NFS server) NO PROBLEM
domU(NFS client) <-- domU(NFS server) NO PROBLEM
domU(NFS client) --> domU(NFS server) NO PROBLEM
I configured NFS export on some other machine on the network and mounted
this export as /home on my domU. There was no problem copying data of
any Size in any direction.
It is not only a Problem of copying data into /home the system crashes
also if I write Data into /home using cat or dd.
It is not a Problem of access rights, I do all the tests as user root,
and as I wrote above the problem only occurs with writes biger then 200
kB. With less it works without any Problem.
I tried to setup the NFS export over the bridge of the external IP
Address, but I also set up an only virtual device "virbr0". The Problem
occurs in either cases.
I can copy data of any Size from domU to dom0 using scp or netcat.
I cannot believe it, but all the tests show, that this problem only
occurs in the one special case described above. Only one direction, only
Is this a Bug or am I doing anything obviously crazy that I have overlooked?
Thank you for your response,
Here some Version Info of the dom0 (the problem occurs independently
from the domU very different domUs have been tested )
[root@dom0 ~]# /usr/sbin/xm info
release : 2.6.21-2950.fc8xen
version : #1 SMP Tue Oct 23 12:24:34 EDT 2007
machine : i686
nr_cpus : 2
nr_nodes : 1
sockets_per_node : 1
cores_per_socket : 2
threads_per_core : 1
cpu_mhz : 1862
total_memory : 2046
free_memory : 126
xen_major : 3
xen_minor : 1
xen_extra : .0-rc7-2950.fc8
xen_caps : xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p
xen_scheduler : credit
xen_pagesize : 4096
platform_params : virt_start=0xf5800000
xen_changeset : unavailable
cc_compiler : gcc version 4.1.2 20070925 (Red Hat 4.1.2-32)
cc_compile_by : kojibuilder
cc_compile_domain : (none)
cc_compile_date : Tue Oct 23 12:22:00 EDT 2007
xend_config_format : 4
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