Setup ZFS ARC Limit
Adaptive Replacement Cache (ARC) is used to improve IO performance, but this can reserved a lot of system memory, maybe reserve to 80% of your Proxmox system.
No problem! This value can be configured and for internet searching result, people recommend setup limit value depend on your ZFS pool size:
- Start 2GB
- Each storage 1TB increase ARC limit for 1GB
Example ZFS pool sizing 2TB we recommended 2GB + (1GB * 2) = 4GB
To change value edit /etc/modprobe.d/zfs.conf add value in bytes:
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options zfs zfs_arc_max=8589934592
options zfs l2arc_noprefetch=0
After edit and save file you need to update system to each restart with follow command:
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update-initramfs -u
Done.
For some value in bytes, calculated as below:
| Size | Bytes |
|---|---|
| 32GB | 34359738368 |
| 16GB | 17179869184 |
| 8GB | 8589934592 |
| 4GB | 4294967296 |
| 2GB | 2147483648 |
| 1GB | 1073741824 |
| 512MB | 536870912 |
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