I did the same test for USB flash memory and it works normally. try create a swap on zvol, it's definitely not working well..
=================================================================== jehos@MacBuntu:~$ sudo fdisk -l /dev/sdc Disk /dev/sdc: 7.46 GiB, 8002732032 bytes, 15630336 sectors Disk model: Cruzer Blade Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 91BE0613-2C00-8944-BEFF-12CCBF5DE2B8 jehos@MacBuntu:~$ sudo mkswap -f /dev/sdc Setting up swapspace version 1, size = 7.5 GiB (8002727936 bytes) no label, UUID=14bb8b5c-ded5-444e-8a62-a21cbc469d08 jehos@MacBuntu:~$ sudo swapon /dev/sdc jehos@MacBuntu:~$ free -m total used free shared buff/cache available Mem: 7870 3106 3843 257 920 4260 Swap: 7631 0 7631 jehos@MacBuntu:~$ time stress --vm 100 -t 10 stress: info: [6247] dispatching hogs: 0 cpu, 0 io, 100 vm, 0 hdd stress: info: [6247] successful run completed in 15s real 0m15.124s user 0m0.736s sys 0m3.536s -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1847628 Title: When using swap in ZFS, system stops when you start using swap To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1847628/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs