Building Disaster Recovery Serviceguard Solutions Using Metrocluster with 3PAR Remote Copy

Table 5 Error Messages and their Resolution (continued)
ResolutionCauseLog Messages
• Passwordless SSH is not configured
from the node to the storage
system.
• The Remote Copy volume group
for DC1 or DC2 may not exist.
Managing connections to 3PAR array
The maximum number of SSH connections to a 3PAR storage array can be 16. Metrocluster
configuration or package startup operations use SSH connections to get information about the
remote copy groups from the storage array. Therefore, more than 16 Metrocluster packages cannot
be configured in a cluster.
The maximum number of CLI connections to a 3PAR storage array is 64.
To decide the actual number of Metrocluster packages that can be configured, consider the
following:
• The number of connections consumed by other Metrocluster configured to failover applications
from the storage array.
• Any external connections made by storage administrators.
If the Metrocluster packages fail to start because SSH or CLI connections are exhausted, do the
following to restart:
• Verify the number of users connected to the array by using the showuserconn command.
Notify the administrators to close the idle sessions. After the number of available connections
is increased, restart the packages.
Troubleshooting connectivity issues to HP 3PAR storage system
During Metrocluster configuration, if you are unable to connect to the HP 3PAR storage system,
ensure that the storage system is up and running, and the network ports are functioning properly.
To check for response from the storage system over the network, use the ping command from
cluster nodes to the storage system's network name or IP address.
# ping <storage system network name or IP address>
If you are using the network name of the storage system, verify it is resolving to proper IP address
using nslookup command from the cluster nodes.
# nslookup <storage system network name>
If the local replication role is secondary, the remote replication role is primary, and the remote
copy link is up, Metrocluster executes stop, reverse, and start operations for the Remote Copy
volume group on the local site. If the stop and reverse operation succeed, the secondary volumes
become read/write and the Metrocluster package comes up even if the start operation fails with
the error "Promote operation is going on". If the start operation fails, replication I/O does not start
from the new primary volumes to the new secondary volumes. In this case, manual intervention is
required to restart the replication using the startcopygroup command.
Troubleshooting Metrocluster SADTA
Logs and files
This section describes the guidelines to be considered before working with files that need to be
configured for SADTA.
60 Troubleshooting