From OpenNMS

Contents 1 Domain/IfAlias Data Storage FAQ 1.1 Q. What is the purpose of Domain/IfAlias Data Storage? 1.2 Q. I don't want these options. What do I have to do to disable them? 1.3 Q. Can I apply these options to some nodes and not others? 1.4 Q. Can I have multiple data collection domains? 1.5 Q. Can I store data collected from a node by both the original nodeid/interface scheme and the optional domain/ifAlias scheme? 1.6 Q. How does the new optional storage scheme interact with the setting of snmpStorageFlag in datacollection-config.xml? 1.7 Q. I want to store data by the optional domain/ifAlias scheme and I also want to store the same data by the original nodeid/interface scheme, but only for the interfaces with non-null ifAliases. Is that possible? 1.8 Q. I want a different combination of storage options for some of the nodes in a domain. Can I do that? 1.9 Q. How can I find out which node and interface currently matches the ifAlias data I'm viewing? 1.10 Q. How can I tell if an ifAlias in my domain is unique? 1.11 Q. What characters can I use in my ifAliases? 1.12 Q I want to create a KSC Performance Report using data stored by domain/ifAlias. Can I do that? 1.13 Q. When I search for an ifAlias I see two interfaces on my router with the same ifAlias even though I've only configured one. What causes this? 1.14 Q. I want to name all the ports on my switch, but I don't want to store data for all of them. Is there a way to do this? 1.15 Q. Why not just collect data on the actual servers or other devices directly rather that collecting interface data from the switch or router they are connected to?

Domain/IfAlias Data Storage FAQ

Q. What is the purpose of Domain/IfAlias Data Storage?

A. See Domain-IfAlias_Data_Storage_How-To.

Q. I don't want these options. What do I have to do to disable them?

A. Nothing. These options are disabled by default. [

Q. Can I apply these options to some nodes and not others?

A. Yes. you do that by putting the two groups of nodes in separate data collection packages in datacollection-config.xml.

Q. Can I have multiple data collection domains?

A. Yes.

Q. Can I store data collected from a node by both the original nodeid/interface scheme and the optional domain/ifAlias scheme?

A. Yes. There are configuration options available in datacollection-config.xml to do this.

Q. How does the new optional storage scheme interact with the setting of snmpStorageFlag in datacollection-config.xml?

A. You have some options here to provide maximum flexibility. For example, you can limit storage to only those interfaces that would store according to the snmpStorageFlag setting or you can override the snmpStorageFlag and store data for any interface in the domain with a non-null ifAlias. See: Domain_ifAlias_storage_matrix.

Q. I want to store data by the optional domain/ifAlias scheme and I also want to store the same data by the original nodeid/interface scheme, but only for the interfaces with non-null ifAliases. Is that possible?

A. Yes.

Q. I want a different combination of storage options for some of the nodes in a domain. Can I do that?

A. Yes. You can divide your nodes into multiple collection packages and still include them in the same domain.

Q. How can I find out which node and interface currently matches the ifAlias data I'm viewing?

A. There are two ways. There will be a link next to the graph that shows you, or you can search for ifAliases from the search page. Note: Recent code changes have removed the link next to the graph.

Q. How can I tell if an ifAlias in my domain is unique?

A. See previous question. Either method will show all matches and partial matches in the system. For example server1 and server12 are unique, but searching for server1 is a partial match for server12 so both will be displayed. It is similar in this respect to searching on node names.

Q. What characters can I use in my ifAliases?

A. Since the ifAlias forms part of the file name used to store the data, characters should be restricted to those normally acceptable in file names. Common practice (and the current implementation of this code) suggests alphanumeric characters, minus (-), period (.), and underscore (_). Other characters can be used in ifAliases, but will get converted to underscore when creating filenames.

Q I want to create a KSC Performance Report using data stored by domain/ifAlias. Can I do that?

A. Yes. You can even mix and match in the same report.

Q. When I search for an ifAlias I see two interfaces on my router with the same ifAlias even though I've only configured one. What causes this?

A. Some devices like cisco routers may have some interfaces listed twice in the DB. For example a vlan may be listed both under the vlan name and the ipaddress used for routing that vlan. In this case the ifIndex should be the same, and you will not get an extra set of data collections. If the ifIndexes are different, then check your router config carefully to make sure there are no duplicate ifAliases. If you're sure one of the entries is bogus, try rescanning the node. or the offending interface may be manually deleted via the OpenNMS GUI.

Q. I want to name all the ports on my switch, but I don't want to store data for all of them. Is there a way to do this?

A. Two ways. Your domain can have a comment character specified. Any text including and following the comment character will be ignored when storing data. To prevent data storage, begin your names with the comment character. Alternatively, you may set the snmpStorageFlag to "select" and configure your domain to control your collection that way.

Q. Why not just collect data on the actual servers or other devices directly rather that collecting interface data from the switch or router they are connected to?

A. Many devices may not have snmp agents, or access from OpenNMS may not be allowed. Also, collecting data from the switch ports means that we need to collect data from fewer devices, since one switch can support many servers or other devices.