From man qm
qm importdisk <vmid> <source> <storage> [OPTIONS]
Import an external disk image as an unused disk in a VM. The image format has to be supported by qemu-img(1).
<vmid>: <integer> (1 - N)
The (unique) ID of the VM.
The ZFS Event Daemon (zed) is in the systemd unit zfs-zed, so to restart it you have to use:
systemctl restart zfs-zed
The path to the zed executable is strange, in fact I have
$ systemctl status zfs-zed
● zfs-zed.service - ZFS Event Daemon (zed)
Without RAID 1, in case of a SSD failure, your server will have a downtime, because you have to reinstall Proxmox and recover the VMs and configuration. I won't do that.
Don't do that, use the whole SSD for your fast pool, if you want more ARC cache, add RAM, always better than ARC L2
Buy another 500 gb ssd, then install proxmox on zfs raid 1 of both ssd, use the rpool (ssd raid1) for VM disks that need speed (operating systems, databases, and so on)
Create a zfs RAID10 on the 4 spinning disks and use this pool for VM disks that store less used datas or datas that need less...
It's changed in the last versions of the installer, now you can reserve some free space on the disk/disks when you install Proxmox and then you can configure swap on that free space
I never needed to do that, it can be dependent on your hardware, your workload, and so on
Your statement is false. Just keep watching the ARC size with
and you'll see by yourself that ARC allocation is dynamic, it grows up when there are request and free memory and it shrinks when there memory is needed (example: you start another VM and there is not enough free RAM). But...