Recovery from RLINK connect problems
This section describes the errors that may be encountered when connecting RLINKs. To be able to troubleshoot RLINK connect problems, it is important to understand the RLINK connection process.
Connecting the Primary and Secondary RLINKs is a two-step operation. The first step, which attaches the RLINK, is performed by issuing the
startrep command. The second step, which connects the RLINKs, is performed by the kernels on the Primary and Secondary hosts.
startrep command is issued, VVR performs a number of checks to ensure that the operation is likely to succeed, and if it does, the command changes the state of the RLINKs from detached/stale to enabled/active. The command then returns success.
If the command is successful, the kernel on the Primary is notified that the RLINK is enabled and it begins to send messages to the Secondary requesting it to connect. Under normal circumstances, the Secondary receives this message and connects. The state of the RLINKs then changes from enabled/active to connect/active.
If the RLINK does not change to the connect/active state within a short time, there is a problem preventing the connection. This section describes a number of possible causes. An error message indicating the problem may be displayed on the console.
If the following error displays on the console:
VxVM VVR vxrlink INFO V-5-1-5298 Unable to establish connection with remote host <remote_host>, retrying
Make sure that the
vradmind daemon is running on the Primary and the Secondary hosts; otherwise, start the
vradmind daemon by issuing the following command:
For an RLINK in a shared disk group, make sure that the virtual IP address of the RLINK is enabled on the logowner.
If there is no self-explanatory error message, issue the following command on both the Primary and Secondary hosts:
vxprint -g diskgroup -l rlink_name
In the output, check the following:
remote_host of each host is the same as
local_host of the other host.
remote_dg of each host is the same as the disk group of the RVG on the other host.
remote_dg_dgid of each host is the same as the
dgid (disk group ID) of the RVG on the other host as displayed in the output of the
remote_rlink of each host is the same as the name of the corresponding RLINK on the other host.
remote_rlink_rid of each host is the same as the
rid of the corresponding RLINK on the other host.
Make sure that the network is working as expected. Network problems might affect VVR, such as prevention of RLINKs from connecting or low performance. Possible problems could be high latency, low bandwidth, high collision counts, and excessive dropped packets.
For an RLINK in a private disk group, issue the following command on each host. For an RLINK in a shared disk group, issue the following command on the logowner on the Primary and Secondary:
There should be no packet loss or very little packet loss. To ensure that the network can transmit large packets issue the following command on each host for an RLINK in a private disk group. For an RLINK in a shared disk group, issue the following command on the logowner on the Primary and Secondary:
ping -s 8192
The packet loss should be about the same as for the earlier
vxiod command on each host to ensure that there are active I/O daemons. If the output is
volume I/O daemons running, activate I/O daemons by issuing the following command:
VVR uses well-known ports to establish communications with other hosts.
Issue the following command to display the port number:
vxprint -g diskgroup
Issue the following command to ensure that the heartbeat port number in the output matches the port displayed by
Confirm that the heartbeat port has been opened by issuing the following command:
netstat -an | grep port-number
port-number is the port number being used by the heartbeat server as displayed by the
The output looks similar to this:
udp4 0 0 *.port-number *.*