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[MX/SRX] Is the 'Top Fan Tray 0 i2c backup not ok, status 0x8 failed 1 times' fan tray log harmful?



Article ID: KB22614 KB Last Updated: 23 Mar 2021Version: 5.0
This article describes the issue of the MX-style chassis, such as SRX5800 or MX960, receiving the Top Fan Tray 0 i2c backup not ok, status 0x8 failed 1 times log message.

 To identify if the Top Fan Tray 0 i2c backup not ok, status 0x8 failed 1 times log is harmful or not.
Your chassis is placed in the perfect (recommended) temperature conditions; but still generates the following log:
Top Fan Tray 0 i2c slave not ok, status 0x8 failed 1 times
Do not worry, as it is a normal log. It can happen for either fan tray. The only time when this log really needs investigation, is when the failed time is greater than 5.

If you see such a message, print it and check the following command outputs to verify if the temperature is within permissible range:
  • show chassis environment
  • show chassis fpc detail
  • show chassis routing-engine

You can find the permissible range via the following command:
show chassis temperature-thresholds

Sample output of the above command:

If the temperatures exceed the permissible range, then check the temperature conditions of where the device is mounted. Make sure that the fan is not being blocked by anything. 

If all the basic checks are done and you still see the failed log message showing the count as more than 5 and the temperature is above the permissible range, open a JTAC case and have it looked at immediately.
Modification History:
2021-03-19: Updated the article terminology to align with Juniper's Inclusion & Diversity initiatives.
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