Created attachment 1736912 [details] VM dumpxml comparison. left: 4.4.4-3 right: 4.4.4-2 Description of problem: When comparing rhv-4.4.4-3 with 4.4.4-2 on how a direct lun disk attached to a VM is identified on the guest OS, there is difference between the two versions. When looking at dumpxml of the same VM, On the 4.4.4-3 it is identified both, by 'serial' and by 'alias name' as opposed to only having the 'alias name' in 4.4.4-2. See image attached. This may break backup vendors using the image id to find the backup disk inside the backup appliance. https://www.ovirt.org/documentation/administration_guide/#sect-Backing_Up_and_Restoring_Virtual_Machines_Using_the_Backup_and_Restore_API It also makes direct LUN and images behave differently. Previously you could find the disk inside a vm by the image id (/dev/disk/by-id/*image-id*), regardless of the type of the disk, but now you have to write special code for each type. For example: on rhv-4.4.4-2 (this is by disk ID): [root@localhost ~]# ls -l /dev/disk/by-id lrwxrwxrwx. 1 root root 9 Nov 29 15:09 scsi-0QEMU_QEMU_HARDDISK_drive-ua-69585e80-5f5e-47fe-8322-f9f132ba78ad -> ../../sda on 4.4.4-3 (this is by lun id): [root@vm-83-53 ~]# ls -l /dev/disk/by-id lrwxrwxrwx. 1 root root 9 Nov 29 15:16 scsi-360002ac000000000000012fe00021f6b -> ../../sda VM dumpXMLs are stored here, in order to compare them: rhv-4.4.4-3 : 4.4.4-3.xml rhv-4.4.4-2 : 4.4.4-2.xml Version-Release number of selected component (if applicable): rhv-4.4.4-3 How reproducible: 100% Steps to Reproduce: 1. Have VM rhel 8.2 2. Attach to it a direct lun disk 3. Compare the dumpxml with: 'virsh -r dumpxml vm-name' 4. Issue ls -l /dev/disk/by-id on the guest to see how the direct lun disk represented Actual results: 4: Identified by direct lun ID lrwxrwxrwx. 1 root root 9 Nov 29 15:16 scsi-360002ac000000000000012fe00021f6b -> ../../sda Expected results: Should have been identified by Disk ID: lrwxrwxrwx. 1 root root 9 Nov 29 15:09 scsi-0QEMU_QEMU_HARDDISK_drive-ua-69585e80-5f5e-47fe-8322-f9f132ba78ad -> ../../sda
Created attachment 1736913 [details] VM dumpxmls
This is due to bz 1859092. We added serial to the LUNs, having the LUN ID. After fixing it back to image ID, when using virtio-scsi interface and pass-through is on it still will be the LUN ID, as always. The other interfaces and when the lun won't be pass-through, the image ID should be set.
Verified on rhv-release-4.4.5-1 Direct lun disk is now identified by the partial disk ID on the guest. [root@vm-13-49 ~]# ls -l /dev/disk/by-id total 0 lrwxrwxrwx. 1 root root 9 Jan 20 11:10 ata-QEMU_DVD-ROM_QM00005 -> ../../sr0 lrwxrwxrwx. 1 root root 9 Jan 20 11:10 scsi-0QEMU_QEMU_HARDDISK_0e1a4432-0f47-481c-aa1f-e1a72e7f0bd9 -> ../../sda lrwxrwxrwx. 1 root root 9 Jan 20 11:10 scsi-SQEMU_QEMU_HARDDISK_0e1a4432-0f47-481c-aa1f-e1a72e7f0bd9 -> ../../sda lrwxrwxrwx. 1 root root 9 Jan 20 11:10 virtio-dd9dd5a7-8ae5-4359-8 -> ../../vda lrwxrwxrwx. 1 root root 10 Jan 20 11:10 virtio-dd9dd5a7-8ae5-4359-8-part1 -> ../../vda1 lrwxrwxrwx. 1 root root 10 Jan 20 11:10 virtio-dd9dd5a7-8ae5-4359-8-part2 -> ../../vda2 lrwxrwxrwx. 1 root root 10 Jan 20 11:10 virtio-dd9dd5a7-8ae5-4359-8-part3 -> ../../vda3