Removing the scsi_mod.use_blk_mq=1 from /etc/default/grub and the mentioned udev rule file, and regenerating initial ramdisk + reboot seems to do the trick, now everything works with default (cfq) I/O scheduler.
Before this comment, and the problem: # cat /sys/block/sda/queue/scheduler [bfq] none # cat /sys/block/sdb/queue/scheduler [none] bfq After I removed the BFQ specific stuffs and everything worked again: # cat /sys/block/sda/queue/scheduler noop deadline [cfq] # cat /sys/block/sdb/queue/scheduler noop deadline [cfq] So, sorry about the noise, maybe it was my fault ... Interestingly, this setup of mine with BFQ worked in 17.10 on other machines with that kernel parameter and udev rule I mentioned in the previous comment. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1762450 Title: [18.04] writing on thumb drives causes hang for write op, shutdown and 'sync' command To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1762450/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
