High Memory Utilization on 9.3

[Wild Weasel]

I recently upgraded to FreeNAS-9.3-STABLE-201412312006 from 9.2.x. Ever since, I've notice memory utilization is nearly 100% all the time -- even when CPU utilization is less than 5%. Anyone else seeing this behavior?

 

[dlavigne]

How much RAM? Post a screenshot of what you are seeing.

 

[Fraoch]

9.3 also tracks the ARC size (in Reporting - ZFS). How big is your ARC in comparison to your total memory?

If the ARC takes up most of your memory, no need to worry, it's using the memory for the largest benefit (caching file transfers). I find ARC starts out low after a reboot and ramps up as transfers occur. Some heavy transfers will have the ARC take up almost 100% of the available memory. However ARC is dynamically adjusted, if the system needs memory for other operations, ARC will be dialed down (and file transfer speeds will suffer a bit). After the file transfer finishes, ARC remains in memory but is inactive and is adjusted if the system requires memory. So you may see memory usage approaching 100% after several file operations and remain there until the next reboot.

 

[nick779]

9.3 also tracks the ARC size (in Reporting - ZFS). How big is your ARC in comparison to your total memory?

If the ARC takes up most of your memory, no need to worry, it's using the memory for the largest benefit (caching file transfers). I find ARC starts out low after a reboot and ramps up as transfers occur. Some heavy transfers will have the ARC take up almost 100% of the available memory. However ARC is dynamically adjusted, if the system needs memory for other operations, ARC will be dialed down (and file transfer speeds will suffer a bit). After the file transfer finishes, ARC remains in memory but is inactive and is adjusted if the system requires memory. So you may see memory usage approaching 100% after several file operations and remain there until the next reboot.

This is really interesting. Not my thread, but this is the exact behavior my box is seeing.

 

[Wild Weasel]

How much RAM? Post a screenshot of what you are seeing.

16 GB, non-ECC. Here's what things look like these days:

 

[Wild Weasel]

9.3 also tracks the ARC size (in Reporting - ZFS). How big is your ARC in comparison to your total memory?

If the ARC takes up most of your memory, no need to worry, it's using the memory for the largest benefit (caching file transfers). I find ARC starts out low after a reboot and ramps up as transfers occur. Some heavy transfers will have the ARC take up almost 100% of the available memory. However ARC is dynamically adjusted, if the system needs memory for other operations, ARC will be dialed down (and file transfer speeds will suffer a bit). After the file transfer finishes, ARC remains in memory but is inactive and is adjusted if the system requires memory. So you may see memory usage approaching 100% after several file operations and remain there until the next reboot.

ARC looks like this (~10G of 16G):

It tends to stay about like this all the time. BTW, the system is used primarily for Plex and content is being consumed fairly regularly. Also, Crashplan is running on the box.