Bug 1118847
Summary: | ovirt-engine currently sets the disk device to "lun" for all virtio-scsi direct LUN connections and disables read-only for these devices | |||
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Product: | Red Hat Enterprise Virtualization Manager | Reporter: | Rob Washburn <rwashbur> | |
Component: | ovirt-engine | Assignee: | Daniel Erez <derez> | |
Status: | CLOSED ERRATA | QA Contact: | Elad <ebenahar> | |
Severity: | high | Docs Contact: | ||
Priority: | unspecified | |||
Version: | 3.4.0 | CC: | amureini, derez, ebenahar, eedri, gklein, iheim, lbopf, lpeer, pbonzini, rbalakri, Rhev-m-bugs, rwashbur, scohen, yeylon | |
Target Milestone: | --- | Keywords: | ZStream | |
Target Release: | 3.5.0 | |||
Hardware: | x86_64 | |||
OS: | All | |||
Whiteboard: | storage | |||
Fixed In Version: | ovirt-engine-3.5.0_rc1.1 | Doc Type: | Enhancement | |
Doc Text: |
Previously, the Red Hat Enterprise Virtualization Manager was configured to set all virtio-SCSI direct LUN devices to the "LUN" device type. This device type does not support direct LUN read-only capability. Now, the Manager sets virtio-SCSI direct LUNs to the "disk" device type when the read-only option is enabled, which enables read-only functionality via SCSI emulation. This functionality is important, in particular, for Cloud Forms Management Engine appliances attempting to run smart-state analysis against Red Hat Enterprise Virtualization data storage domains with a large number of backing LUNs.
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Story Points: | --- | |
Clone Of: | ||||
: | 1125373 (view as bug list) | Environment: | ||
Last Closed: | 2015-02-11 18:05:46 UTC | Type: | Bug | |
Regression: | --- | Mount Type: | --- | |
Documentation: | --- | CRM: | ||
Verified Versions: | Category: | --- | ||
oVirt Team: | Storage | RHEL 7.3 requirements from Atomic Host: | ||
Cloudforms Team: | --- | Target Upstream Version: | ||
Embargoed: | ||||
Bug Depends On: | ||||
Bug Blocks: | 1125373, 1142923, 1156165 |
Description
Rob Washburn
2014-07-11 16:52:17 UTC
This may be related to change I7ceffe36e1145d4783c94f62043dfad694fdd290. Daniel, please take a look? moving to 3.4.2, build for 3.4.1 is already closed for accepting new bugs. Quoting my reply on the upstream gerrit, I think this approach is not a good one. If you change 'lun' to 'disk' (or vice versa) the /dev/disk stable paths to the disks change, and the guest might be relying on them. Similarly, Windows might think the disk is a new one and it may not bring it online or it may assign a different disk letter. To provide full flexibility there should be two choices: - emulated/passthrough ('disk' vs. 'lun') - if emulated, read-only/read-write When QEMU adds support, passthrough read-only can be supported too. (In reply to Paolo Bonzini from comment #4) > Quoting my reply on the upstream gerrit, I think this approach is not a good > one. If you change 'lun' to 'disk' (or vice versa) the /dev/disk stable > paths to the disks change, and the guest might be relying on them. > Similarly, Windows might think the disk is a new one and it may not bring it > online or it may assign a different disk letter. > > To provide full flexibility there should be two choices: > > - emulated/passthrough ('disk' vs. 'lun') > - if emulated, read-only/read-write > > When QEMU adds support, passthrough read-only can be supported too. I agree with you completely - this would necessitate a UX change at the ovirt-engine level to ensure that the user can pick and choose their desired virtio-scsi device flags. The current ovirt-engine UX only allows virtio-scsi "lun" device types (implicitly) for virtio-scsi direct LUNs presented to VMs. Attaching a direct LUN connected by virt-IO-SCSI as RO is greyed out in webadmin. Re-opening. Checked with ovirt-3.5 RC1 When attaching a direct LUN connected to a VM by virt-IO-SCSI, the device is set to 'disk' <disk device="disk" snapshot="no" type= "block"> <address bus="0" controller="0" target="0" type="drive" unit="1"/> <source dev="/dev/mapper/3514f0c5462600003"/> <target bus="scsi" dev="sda"/> <readonly/> <serial></serial> <driver cache="none" error_policy="stop" io="native" name="qemu" type="raw"/> </disk> Verified that the disk is write protected by the OS. Verified using ovirt-3.5-RC1.1 oVirt Engine Version: 3.5.0-0.0.master.20140821064931.gitb794d66.el6 Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHSA-2015-0158.html |