The iostat -mx shows that the /dev/sdb /dev/sdc devices have a very high read I/O latency of ~80-110 milliseconds which may be the underlying issue.
I suggest seeing how long it takes to read data from these raw devices to sanity check their maximum speed. One can do this by doing: sync echo 3 | sudo tee /proc/sys/vm/drop_caches dd if=/dev/sdb of=/dev/null bs=512 count=1048576 ..and wait for 512MB of data to be read and see what the read speed is of the raw device. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1725859 Title: zfs frequently hangs (up to 30 secs) during sequential read To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1725859/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
