This is something new to me.
Video being recorded and saved to a fast SSD, normally it affects my CPU like +10% maybe and the CPU utilization is around 20%, but when there was a high CPU iowait (likely due to a overload of the external USB data HDD), the recorded video seemed like skipping frames and freezing. During the record, i have seen the htop utility is visualizing the iowait on the CPU threads and the iowait was majority of the threads capacity.
I doubt this was caused by bottleneck on the SSD NVMe, even i have seen quite high activity 30MB read and 30MB write due to possibly swapping (most of the RAM is shown to be utilized by cache, which is OK, then it was overflowing to swap. It is quite strange to me that the cache ate majority of the RAM capacity and then was swapping to a disk, instead of freeing some cache. my swappiness is 60 and i am having zswap, $ systemd-swap:
When i have paused some HDD tasks, the iowait portion of the CPU threads load dropped significantly and the recorded video had no issues.
QUESTION: Is there anything i can do to prevent the video being influenced by the external drive overload?
I know i can run an app using nice and ionice. Which one do you think may help, if any?
Or is there any other way to prevent it, beside buying additional drives or getting SSDs for the data? Thank you
Video being recorded and saved to a fast SSD, normally it affects my CPU like +10% maybe and the CPU utilization is around 20%, but when there was a high CPU iowait (likely due to a overload of the external USB data HDD), the recorded video seemed like skipping frames and freezing. During the record, i have seen the htop utility is visualizing the iowait on the CPU threads and the iowait was majority of the threads capacity.
I doubt this was caused by bottleneck on the SSD NVMe, even i have seen quite high activity 30MB read and 30MB write due to possibly swapping (most of the RAM is shown to be utilized by cache, which is OK, then it was overflowing to swap. It is quite strange to me that the cache ate majority of the RAM capacity and then was swapping to a disk, instead of freeing some cache. my swappiness is 60 and i am having zswap, $ systemd-swap:
This is Arch Linux.
When i have paused some HDD tasks, the iowait portion of the CPU threads load dropped significantly and the recorded video had no issues.
QUESTION: Is there anything i can do to prevent the video being influenced by the external drive overload?
I know i can run an app using nice and ionice. Which one do you think may help, if any?
Or is there any other way to prevent it, beside buying additional drives or getting SSDs for the data? Thank you
