Article ID: 127972, created on Jan 6, 2016, last review on Jun 17, 2016

  • Applies to:
  • Virtuozzo 6.0

Symptoms

prlctl commands to remote server get stuck, for example:

  • prlctl migrate ct101 10.0.0.10

    Login failed: Connection to Parallels Service was lost. There may be connection problems or the server may be down. Contact your Parallels Server administrator for assistance. 
    
  • prlctl backup ct101 -s 10.0.0.10

    Login failed: PrlJob_Wait: Operation timeout. The operation could not be completed due to a timeout. 
    

Both servers configured with MTU 9000

[root@pcs1 ~]# ifconfig eth0 | egrep 'inet|MTU'
          inet addr:10.0.0.9  Bcast:217.115.117.255  Mask:255.255.255.0
          inet6 addr: fe80::2e0:81ff:feb8:4de1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:9000  Metric:1

ping with large packets not going through

[root@pcs1 ~]# ping -s 8550 10.0.0.10 -c 4
PING 10.0.0.10 (10.0.0.10) 8550(8578) bytes of data.
--- 10.0.0.10 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 12999ms

Cause

The neighbour switch is not capable of processing jumbo frames, which breaks proper network communication between the dispatchers

Resolution

Resolve the issues with the network switch: make sure it supports jumbo frames and this functionality is enabled.

As a temporary workaround, MTU can be decreased to 1500.

# ip link set mtu 1500 dev eth0

For Virtuozzo Storage see also:

Newly added MDS server becomes stale/unavailable

Search Words

backup

migration

restore

WARNING: callback took too much time: This is absolutely incorrect! Callback must be rewritten!

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