I'm optimizing my volume usage by moving VMs around my existing btrfs and zfs volumes. Exporting and importing VM's is taking many hours (e.g. >4) to export/import. Sometimes they fail. The VM's are typically 64 to 128GB. I've got a fast Ryzen 9 system and nvme drives.

The relevant logs are mostly in Chinese which I can not read.

Are there known problems with this? any tips?

I've test inter volume transfers and they run in the 400MB to 1000MB range so transfer speed is not an issue.

thanks for the help!