Do you have auditing for config changes enabled?

# isi audit settings view        

[...]

  Config Auditing Enabled: Yes

[...]

If it is turned off now, but was on at the time when the changes were made,

the audit files are still retained in  /ifs/.ifsvar/audit/logs/node*/config/ .

Audits can be viewed per node with something like:

isi_audit_viewer -t config -s '2015-01-01' -e '2015-01-31' -n 1

Params are start/end date and node number.

hth

-- Peter