Description of problem: It reports a minimum_io_size of 32MB (!) instead of 512 bytes, causing all kinds of fun and weirdness. For example parted will create partitions with enormous alignments, and LVM2 refuses to work on smaller disks. ==> /sys/block/sda/queue/minimum_io_size <== 33553920 This circus is fixed by: commit 37c51741892a89cf5710f5ac231091fb0a6352c7 Author: Fam Zheng <famz> Date: Wed Mar 28 00:41:41 2018 +0800 scsi-disk: Don't enlarge min_io_size to max_io_size Some backends report big max_io_sectors. Making min_io_size the same value in this case will make it impossible for guest to align memory, therefore the disk may not be usable at all. Do not enlarge them when they are zero. Version-Release number of selected component (if applicable): qemu-2.12.0-0.5.rc1.fc29.x86_64 qemu-2.12.0-0.6.rc2.fc29.x86_64 and both affected How reproducible: 100% Steps to Reproduce: $ guestfish scratch 64M : run : debug sh "cat /sys/block/sda/queue/minimum_io_size" 512 => working 33553920 => broken
Fix included in -rc3 package: qemu-2.12.0-0.7.rc3.fc29 https://koji.fedoraproject.org/koji/taskinfo?taskID=26395119