Proxmox NFS Configuration

NFS Configuration for Proxmox

When Using Truenas as a disk source for proxmox VM's I ran into issues with the write speed of the disks stored on the NFS share, mounted on the Truenas Scale server. The issue seemed to be related to the file syncing properties of ZFS, and was allowing strong read speeds, but abysmal write speeds, as it was attempting to write sync all of the data being written from the VM OS.

Note: For some instances, such as using TrueNAS Scale, I had to call the zfs command with the full path /usr/sbin/zfs

Here's a basic outline of how you might achieve

First, you'll need to identify the dataset associated with your NFS share. You can do this by listing the datasets:

zfs list

Look for the dataset that corresponds to your NFS share.

Modify the Sync Property: Once you've identified the dataset, you can modify its sync property to change the sync behavior. The available options for the sync property are typically standard, always, or disabled. To set the sync property to asynchronous (disabled):

zfs set sync=disabled pool_name/dataset_name

Replace pool_name/dataset_name with the actual name of your dataset.

For example:

zfs set sync=disabled tank/my_nfs_share

Verify Changes: After making this change, you can verify the updated property settings

zfs get sync pool_name/dataset_name

This command will display the current value of the sync property for the specified dataset.

Remember, adjusting the sync property to asynchronous might improve performance in certain scenarios, but it also introduces a higher risk of data loss in case of unexpected power loss or system crashes. Ensure that you understand the implications before making such changes, and always have proper backups and safeguards in place for your data.

Please replace pool_name/dataset_name with the actual names of your pool and dataset when executing these commands to modify the sync property accordingly.