Troubleshoot Storage

 

 


 

dmesg Log

2017-06-15T08:20:52.679Z cpu22:36664)WARNING: ScsiDeviceIO: 1243: 
Device naa.6782bcb0138478001f540cc410d12907 performance has deteriorated. 
I/O latency increased from average value of 5444 microseconds to 178356 microseconds.

原因

 - High device latency

 - Overload conditions on the device

 - LUN replication tool is running

High device latency

If the device latency is too high for a consistent period of time,
check the storage performance by verifying the logs on the storage array for any indication of a failure.
If failures are logged on the storage array side, take corrective actions.
Contact your storage vendor for information regarding checking logs on the array.

Also, check if these messages are generated when there were any scheduled tasks,
such as backups or replications, as these can also cause intermittent performance hits.

Overload conditions on the device

If the message is generated because of an overload condition,
attempt to reduce the load on the affected storage device.

LUN replication tool is running

If running a LUN replication tool,
pause the task from the storage end and attempt a storage vMotion to a different datastore.
This should help improve the I/O operations.

會用到的 Debug cmd

http://datahunter.org/esxi_cli#storage

 

 

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