Understanding the IBM TotalStorage Open Software Family

182 Understanding the IBM TotalStorage Open Software Family

Log events

Tivoli SAN Manager collects events received from devices. Figure 4-26 shows an

example of events logged by one of the switches.

Figure 4-26 Switch events

Highlight faults

Events about SAN components are communicated to IBM Tivoli SAN Manager

by Agents. IBM Tivoli SAN Manager logs the events in a log that looks like

Figure 4-26 above. IBM Tivoli SAN Manager then evaluates the event, and

decides if the event is (or is not) a fault.

If the event is a fault, IBM Tivoli SAN Manager indicates the change in status by

changing the color of the object in the topology map. Here is just one example,

where we simulate the loss of the switch by powering it off. Other common faults

include a Fibre Channel cable breaking, a host crash, and an unavailable storage

frame.

Chapter 4. Storage resource management 183

Figure 4-27 shows the topology display once it is refreshed. The healthy devices

are in green, and the unhealthy devices are in red. We have also circled the

devices that turned red for clarity.

Figure 4-27 Map Showing Effects of Switch Losing Power

򐂰 Device #5, the switch, is obvious. The power went out, so the switch no

longer responds.

򐂰 All the links (connections) from the switch to the devices also went red.

򐂰 The Devices 1, 2, 3, and 4 went red. These devices have no Agent on them,

are known to IBM Tivoli SAN Manager only through the switch name server,

and are unavailable now that the switch is down. IBM Tivoli SAN Manager’s

map displays this accurately.

򐂰 The hosts with Agents on them (CRETE, TUNGSTEN, SENEGAL, and

DIOMEDE) remain green, as they still communicate with the Server via

TCP/IP. Only their connection link to the switch turns red.

1

2

3

4

5

184 Understanding the IBM TotalStorage Open Software Family

When the switch is fixed, as it powers up, it will send an event back to the IBM

Tivoli SAN Manager, who will re-query the switch (running both the topology

scanner and the attribute scanner). The topology will be refreshed to reflect the

switch being back online.

Provide various reports

The primary business purpose for IBM Tivoli SAN Manager is to keep the

storage infrastructure running to support revenue-generating actives. We have

already seen how the topology display will automatically update to reflect devices

becoming available so that network administrator can quickly respond.

Another way to improve availability is to use monitoring and reports to anticipate

devices that are beginning to fail.

Not all failures can be predicted; however, many devices may fail gradually over

time, so reporting a history of problems can help anticipate this. For example, if

you see a lot of transmission errors occurring over a period of time, you might

anticipate a component failure, and schedule maintenance testing or preemptive

replacement to minimize impact on generating revenue or other critical

applications.

Reporting is provided by NetView and includes historical and real-time reporting,

on an individual device, or on a defined group of devices.

With NetView, you have a very flexible capability to build your own reports

according to your specific needs. The reports we are interested in for IBM Tivoli

SAN Manager are reports against the objects in the MIB provided by the switch

vendor. In our lab, we used an IBM 2109 16-port switch, so we used the Brocade

MIB for the Brocade Silkworm 2800.

The data elements in the MIB can report on status (device working or not

working) and performance (x frames were transmitted over this switch port in Y

seconds).

Historical reporting

With NetView, you can display historical reports based on data collected.

Figure 4-28 on page 185 shows a report of data collected over eight ports in a

two minute interval. You can set up the data collection to look for thresholds on

various MIB values, and send a trap when defined values are reached.

Chapter 4. Storage resource management 185

Figure 4-28 Graph of # Frames Transmitted over 8 ports in a 2 minute interval

Combining the MIB objects with the canned and customized reporting from

NetView provides the storage administrator with the tools needed to help keep

the SAN running all the time.

Real-time reporting

NetView can also track MIB values in real-time. Figure 4-29 on page 186 shows

real-time monitoring of traffic on switch ports. The graph shows the number of

frames transmitted from a specific port on a particular switch over a specified

time interval. You can set the polling interval to show how often the graph will

update.