Add testcase to verify max informational error log

Added test case:
- Verify Informational Error Log Size When Error Log Exceeds Limit

Change-Id: Icba1d0d3d716a63390aa96f1940965d614679e1c
Signed-off-by: manashsarma <manashsarma@in.ibm.com>
diff --git a/openpower/pel/test_bmc_pel.robot b/openpower/pel/test_bmc_pel.robot
index 8585c30..f1765c6 100644
--- a/openpower/pel/test_bmc_pel.robot
+++ b/openpower/pel/test_bmc_pel.robot
@@ -43,6 +43,8 @@
 
 @{mandatory_pel_fileds}   Private Header  User Header  Primary SRC  Extended User Header  Failing MTMS
 
+${info_log_max_usage_percentage}  15
+
 
 *** Test Cases ***
 
@@ -518,8 +520,46 @@
     Should Contain  ${pel_records['${id}']['Sev']}  Unrecoverable
 
 
+Verify Informational Error Log Size When Error Log Exceeds Limit
+    [Documentation]  Verify informational error log size when informational log size exceeds limit.
+    [Tags]  Verify_Informational_Error_Log_Error_Log_When_Size_Exceeds_Limit
+
+    # Initially remove all logs.
+    Redfish Purge Event Log
+
+    # Create 3001 information logs.
+    FOR  ${LOG_COUNT}  IN RANGE  0  3001
+      BMC Execute Command  ${CMD_INFORMATIONAL_ERROR}
+    END
+
+    # Delay for BMC to perform log compression when log size exceeds.
+    Sleep  10s
+
+    # Check logsize and verify that disk usage is around 15%.
+    ${usage_percent}=  Get Disk Usage For Error Logs
+    ${percent_diff}=  Evaluate  ${usage_percent} - ${info_log_max_usage_percentage}
+    ${percent_diff}=   Evaluate  abs(${percent_diff})
+    Should Be True  ${percent_diff} <= 0.5
+
+
 *** Keywords ***
 
+Get Disk Usage For Error Logs
+    [Documentation]  Get disk usage percentage for error logs.
+
+    ${usage_output}  ${stderr}  ${rc}=  BMC Execute Command  du  /var/lib/phosphor-logging/errors
+
+    ${usage_output}=  Fetch From Left  ${usage_output}  \/
+
+    # Covert disk usage unit from KB to MB.
+    ${usage_output}=  Evaluate  ${usage_output} / 1024
+
+    # Logging disk capacity limit is set to 20MB. So calculating the log usage percentage.
+    ${usage_percent}=  Evaluate  ${usage_output} / 20 * 100
+
+    [return]  ${usage_percent}
+
+
 Create Test PEL Log
     [Documentation]  Generate test PEL log.
     [Arguments]  ${pel_type}=Internal Failure