How to clear the Alert history in the Exadata.

[root@sinacel05 ~]# cellcli
CellCLI: Release 11.2.3.1.1 - Production on Tue Feb 09 16:11:29 SGT 2016

Copyright (c) 2007, 2011, Oracle.  All rights reserved.
Cell Efficiency Ratio: 1

CellCLI>   LIST ALERTHISTORY WHERE severity = 'critical'  AND examinedBy = '' DETAIL

        name:                   2_1
         alertMessage:           "Cell configuration check discovered the following problems:   Check Exadata configuration via ipconf utility Verifying of Exadata configuration file /opt/oracle.cellos/cell.conf Error. Exadata configuration file not found /opt/oracle.cellos/cell.conf [INFO] The ipconf check may generate a failure for temporary inability to reach NTP or DNS server. You may ignore this alert, if the NTP or DNS servers are valid and available. [INFO] You may ignore this alert, if the NTP or DNS servers are valid and available. [INFO] As root user run /usr/local/bin/ipconf -verify -semantic to verify consistent network configurations."
         alertSequenceID:        2
         alertShortName:         Software
         alertType:              Stateful
         beginTime:              2015-10-06T16:10:23+08:00
         endTime:                2015-10-06T16:24:17+08:00
         examinedBy:
         metricObjectName:       checkconfig
         notificationState:      0
         sequenceBeginTime:      2015-10-06T16:10:23+08:00
         severity:               critical
         alertAction:            "Correct the configuration problems. Then run cellcli command:   ALTER CELL VALIDATE CONFIGURATION   Verify that the new configuration is correct."

         name:                   2_2
         alertMessage:           "Cell configuration check discovered the following problems:   Check Exadata configuration via ipconf utility Verifying of Exadata configuration file /opt/oracle.cellos/cell.conf Checking NTP server on 192.168.1.254                                                             : FAILED Error. Overall status of verification of Exadata configuration file: FAILED [INFO] The ipconf check may generate a failure for temporary inability to reach NTP or DNS server. You may ignore this alert, if the NTP or DNS servers are valid and available. [INFO] You may ignore this alert, if the NTP or DNS servers are valid and available. [INFO] As root user run /usr/local/bin/ipconf -verify -semantic to verify consistent network configurations."
         alertSequenceID:        2
         alertShortName:         Software
         alertType:              Stateful
         beginTime:              2015-10-06T16:24:17+08:00
         endTime:                2015-10-20T19:43:44+08:00
         examinedBy:
         metricObjectName:       checkconfig
         notificationState:      0
         sequenceBeginTime:      2015-10-06T16:10:23+08:00
         severity:               critical
         alertAction:            "Correct the configuration problems. Then run cellcli command:   ALTER CELL VALIDATE CONFIGURATION   Verify that the new configuration is correct."

         name:                   2_3
  alertMessage:           "Cell configuration check discovered the following problems:   Check Exadata configuration via ipconf utility Verifying of Exadata configuration file /opt/oracle.cellos/cell.conf Checking NTP server on 192.168.1.254                                                             : FAILED Error. Overall status of verification of Exadata configuration file: FAILED [INFO] The ipconf check may generate a failure for temporary inability to reach NTP or DNS server. You may ignore this alert, if the NTP or DNS servers are valid and available. [INFO] You may ignore this alert, if the NTP or DNS servers are valid and available. [INFO] As root user run /usr/local/bin/ipconf -verify -semantic to verify consistent network configurations.  The hardware and firmware are not supported. See details below  [PCISlot:HBA:LSIModel:LSIhw:MPThw:LSIfw:MPTBios:DOM:OSDevice:DOMMake:DOMModel:DOMfw:CountAuraCountDOM] Requires:  AllSlots_AllHBAs SAS1068E B3orC0 105 011b5c00 06.26.00.00 AllDOMs_NotApplicable MARVELL SD88SA02 D20Y  4_16   Found:  2 3 SAS1068E B3orC0 105 011b5c00 06.26.00.00 1 /dev/sdv MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  2 3 SAS1068E B3orC0 105 011b5c00 06.26.00.00 2 /dev/sdw MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  2 3 SAS1068E B3orC0 105 011b5c00 06.26.00.00 3 /dev/sdx MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  2 3 SAS1068E B3orC0 105 011b5c00 06.26.00.00 4 /dev/sdy MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  4 1 SAS1068E B3orC0 105 011b5c00 06.26.00.00 1 /dev/sdn MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  4 1 SAS1068E B3orC0 105 011b5c00 06.26.00.00 2 /dev/sdo MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  4 1 SAS1068E B3orC0 105 011b5c00 06.26.00.00 3 /dev/sdp MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  4 1 SAS1068E B3orC0 105 011b5c00 06.26.00.00 4 /dev/sdq MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  5 2 SAS1068E B3orC0 105 011b5c00 06.26.00.00 1 /dev/sdr MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  5 2 SAS1068E B3orC0 105 011b5c00 06.26.00.00 2 /dev/sds MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  5 2 SAS1068E B3orC0 105 011b5c00 06.26.00.00 3 /dev/sdt MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16  5 2 SAS1068E B3orC0 105 011b5c00 06.26.00.00 4 /dev/sdu MARVELL SD88SA02 D20Y DOMS_found_12_but_expected_16   The hardware and firmware are not supported. See details above"

CellCLI> drop alerthistory all ======> command to clear the Alert history

Alert 2_1 successfully dropped
Alert 2_2 successfully dropped
Alert 2_3 successfully dropped
Alert 2_4 successfully dropped
Alert 10_1 successfully dropped
Alert 10_2 successfully dropped

CellCLI> LIST ALERTHISTORY WHERE severity = 'critical'



CellCLI> drop alerthistory all

Alert 2_1 successfully dropped
Alert 2_2 successfully dropped
Alert 6_1 successfully dropped
Alert 6_2 successfully dropped

CellCLI> LIST ALERTHISTORY WHERE severity = 'critical'

CellCLI>




Regards
Gurudatta N.R