[Users] Vzmigrate fails with error "iptables-save exited with 1"

[Corrado Fiore]

Dear All,

I'm trying to migrate online a VPS but I keep seeing the following error:

============================
Live migrating container...
  Copying top ploop delta with CT suspend
Sending /vz/private/10004/root.hdd/root.hdd
Setting up checkpoint...
       suspend...
       get context...
Checkpointing completed successfully
  Dumping container
Setting up checkpoint...
       join context..
       dump...
Can not dump container: Invalid argument
Error: iptables-save exited with 1
Checkpointing failed
Error: Failed to dump container
Resuming...
============================

Notes:

1)  The container keeps working on the original node after the aborted attempt to migrate.

2)  I have tried to manually issue `iptables-save` on the destination node and it works.

3)  I know that the destination node must have loaded all the required IPtables modules.  These are the relevant lines:


====  ORIGIN NODE  ====

[root at node16 /]# uname -a
Linux node16.xxxxx.com 2.6.32-042stab093.4 #1 SMP Mon Aug 11 18:47:39 MSK 2014 x86_64 x86_64 x86_64 GNU/Linux

[root at node16 /]# yum list installed | grep ploop
ploop.x86_64         1.12-1             @openvz-utils                           
ploop-lib.x86_64     1.12-1             @openvz-utils      

[root at node16 /]# lsmod | grep ip
nf_conntrack_ipv4       9946  2 nf_nat
nf_defrag_ipv4          1531  1 nf_conntrack_ipv4
nf_conntrack           80313  4 vzrst,nf_nat,nf_conntrack_ipv4,vzcpt
ip6t_REJECT             4711  0 
ip6table_mangle         3669  0 
ip6table_filter         3033  0 
iptable_mangle          3493  0 
iptable_filter          2937  0 
xt_multiport            2716  0 
ipt_REJECT              2399  0 
ip_tables              18119  2 iptable_mangle,iptable_filter
ip6_tables             18988  2 ip6table_mangle,ip6table_filter
ipv6                  322874  3 vzrst,ip6t_REJECT,ip6table_mangle


====  DESTINATION NODE  ====

[root at node17 /]# uname -a
Linux node17.xxxxx.com 2.6.32-042stab093.4 #1 SMP Mon Aug 11 18:47:39 MSK 2014 x86_64 x86_64 x86_64 GNU/Linux

[root at node17 /]# yum list installed | grep ploop
ploop.x86_64         1.12-1             @openvz-utils                           
ploop-lib.x86_64     1.12-1             @openvz-utils                  

[root at node17 /]# lsmod | grep ip
iptable_nat             6302  0
nf_nat                 23213  2 iptable_nat,vzrst
nf_conntrack_ipv4       9946  3 iptable_nat,nf_nat
nf_defrag_ipv4          1531  1 nf_conntrack_ipv4
nf_conntrack           80313  5 iptable_nat,vzrst,nf_nat,nf_conntrack_ipv4,vzcpt
ip6t_REJECT             4711  0
ip6table_mangle         3669  0
ip6table_filter         3033  0
iptable_mangle          3493  0
iptable_filter          2937  0
xt_multiport            2716  0
ipt_REJECT              2399  0
ip_tables              18119  3 iptable_nat,iptable_mangle,iptable_filter
ip6_tables             18988  2 ip6table_mangle,ip6table_filter
ipv6                  322874  3 vzrst,ip6t_REJECT,ip6table_mangle


In fact, all the relevant modules are present on the destination node AFAICT.  What am I missing here?

Thanks,
Corrado Fiore