Brocade Fabric Manager Administrator's Guide v6.1.0 (53-10000610-02, June 2008)

Fabric Manager Administrator’s Guide 111
53-10000610-02
Performance monitoring components
8
Fabric Manager sets monitors in the fabric only if the total monitor count is 4000 or less. If the
number of monitors is greater than 4000, monitors are not set on any ports.
Granularity
Granularity is the timeframe for the sample values that are used to generate a report. Since Fabric
Manager stores a limited number of samples for each granularity, every level of granularity is not
available for all possible time ranges. For example, if you select a timeframe to be the past three
days, the five-minute granularity level is not available. The options for granularity (for both Port
Statistics and End-to-End Monitoring) are listed in Table 10.
There might be gaps in the stored data for end-to-end monitoring. There are no gaps for port
statistics monitoring.
You do not need to log in to all the switches when you are capturing port statistics data collection
because the data is collected through SNMP. Log in to the seed switch; any unreachable switches
will display a zero value.
Gaps in data for end-to-end monitoring are caused by the following events:
• Authentication failures
Fabric Manager uses switch user names and passwords to store data. If the password is
changed on a switch where performance monitoring is enabled (resulting in an authentication
failure), data collection fails (creating a gap in the stored data).
• Switch not reachable
Data is not gathered if the seed switch is unreachable. If the seed switch is reachable, but
additional switches in the fabric are unreachable by Ethernet, the data is gathered.
• Performance monitoring being disabled
Data is not being gathered, causing a gap in the stored data.
NOTE
For end-to-end monitoring only, if data is not available for some of the granularity points when values
are rolled up to the next time period value, the missing data is ignored. For example, if five of six
5-minute values are 50, and the sixth value is missing: N1= 50, N2= 50, N3=50, N4= 50, N5= 50,
N6= NA. The rolled up value for 30-minute entry=250 (because the N6 value is calculated as if it is
a value of zero).
TABLE 10 Stored samples (per fabric) for granularity options
Granularity Samples Time covered in stored samples
5 minutes 600 2 days and 2 hours
30 minutes 700 2 days and 2 hours, plus 12.5 days
2 hours 775 2 days and 2 hours, plus 12.5 days, plus 50 days
1 day 797 2 days and 2 hours, plus 12.5 days, plus 50 days, plus 732 days (rounded to 797 days)