Hi Eugene,
I think using the below command, you can purge sample from the history tables of dfm.Which will help you delete some of the growth and trend graphs for the specified period.(In your case when before turning on netapp technologies.)
[root@lnx ~]# dfm purgehistory help
NAME
purgehistory -- purge history samples from various DFM history tables.
SYNOPSIS
dfm purgehistory timerange -c <column-name> -t <start-timestamp>
-T <end-timestamp> [-s] [-N <replacement-value>] <table-name>
dfm purgehistory valuerange -c <column-name> {-m <min-purge-value> |
-M <max-purge-value> | -m <min-purge-value> -M <max-purge-value>}
[-s] [-N <replacement-value>] <table-name>
DESCRIPTION
The purgeHistory command neatens a DFM history table by cleaning spikes in
history samples.
table-name
Table name containing history samples.
-c column-name
Column name containing the sample history value.
-t start-timestamp
Starting timestamp value of history samples for column <column-name>.
-T end-timestamp
Ending timestamp value of history samples for column <column-name>.
-m min-purge-value
Minimum purge value of history samples for column <column-name>.
If this is the only option given, then all history samples above
this value are purged.
-M max-purge-value
Maximum purge value of history samples for column <column-name>.
If this is the only option given, then all history samples below
this value are purged.
-N replacement-value
When provided, all purged history sample values for column
<column-name> are substituted with <replacement-value>.
Default value is zero.
-s
Show the list of history samples for column <column-name> without
cleaning them from them history tables.
[root@lnx~]
Regards
adai