PowerFlex: SDCs I/O errors after adding SDS with Single IP

Impact

SDCs may lose the ability to access its volumes.

An SDS was added to an existing cluster. In this case, each existing SDS is configured with 4 IPs and is using IP roles. The new SDS was added in with only one IP. In this case, the IP was on an SDS to SDS only subnet. This allowed the Storage Pools to migrate data on to this SDS. Once the SDCs got the new mapping of the data, the SDCs attempted to connect to this SDS, but the SDS did not have a configured IP to allow any SDC connections. The SDCs cannot access the SDS.

In the MDM event logs, we can see that only one IP was configured when the SDS was added:

 

2020-04-08 11:14:57.251 MDM_CLI_CONF_COMMAND_RECEIVED INFO      Command add_sds received, User: 'admin'. [4574194] protection_domain pdX  fault_set N/A New SDS name: sdsX Hostname: 172.17.16.38  Port: 7072

After incorrectly adding an SDS into an existing cluster, you can add additional IPs to the SDS configuration 

When an SDS is added to an existing cluster, it is best practice to add all IPs and configure them with the correct IP roles.