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Swap utilization alerts and high %iowait

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Article ID: 164003

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Updated On:

Products

Messaging Gateway

Issue/Introduction

Some time after updating to Messaging Gateway (SMG) 10.7 the SMG system begins generating alerts indicating that swap utilization has exceeded 60%. Additionally, SNMP monitoring of cpu resources may begin reporting %iowait in excess of 25%.

Symantec Messaging Gateway Alert Notification for [email protected]

======================= ALERT NOTIFICATION ================================               

The swap space utilization on the following hosts has reached the threshold (60%):  
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Host                     Swap used                Swap free                Date
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smg-in1                  6,664,864 KB (64%)       3,870,120 KB (36%)       Mon Nov 28 11:35:13 PST 2016
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Environment

Messaging Gateway

Cause

This is a known issue resulting from memory utilization by the conduit process which manages anti-spam rule updates. If left running for long periods of time uninterrupted the conduit process will grow large enough to consume significant amounts of swap space and increase the %iowait cpu metric as the kernel pages process data between physical memory and swap.

Resolution

This issue has been addressed with the SMG 10.7.3 release.

Workaround

Any operation which restarts the conduit process will reset memory utilization. These operations include

  • Selecting "Conduit" in the Control Center Administration > Configuration > host > Services page and clicking "Stop" then "Start"
  • Running 'service connector restart' from the SMG command line
  • Rebooting the appliance or virtual machine