eG Help

Consistency points (CP) are periodic tasks performed by Data ONTAP wherein unwritten data that is temporarily stored in the non- volatile RAM (NVRAM), is copied over (committed) to the disks thereby maintaining system consistency.

Typically, a CP occurs when the NVRAM journal is half full or when 10 seconds have passed since the most recent CP, whichever comes first. By carefully studying the number and frequency of CPs, you can accurately determine the level of write activity on your storage system. This test serves as a good indicator of the write request load on your storage system, as it reports the number of CPs that occurred and when it occurred.

Measurement	Description	Measurement Unit	Interpretation
Log_Full_Ops	Indicates the number of consistency point operations that occurred due to the cache i.e., the NVRAM log being full during the last measurement period.	Number	The storage system automatically triggers a consistency point when the NVRAM log is 50% full and writes the data available in the NVRAM log to the disk. By doing so, the write latency of the disk is maintained along with a smooth transition of data to the disk from the NVRAM log.
Cp_Ops	Indicates the number of back to back consistency point operations that occurred during the last measurement period.	Number	The back to back consistency point operations indicate that the storage system is highly loaded and the write rate on the disk is more than the consistency point rate.
Total_Ops	Indicates the total number of consistency point operations that occurred during the last measurement period.	Number	This is a good indicator of the level of write activity on the storage system.