Bug 1897160

Summary: SCSI Pass-Through is enabled by default
Product: [oVirt] ovirt-engine Reporter: Nir Soffer <nsoffer>
Component: BLL.StorageAssignee: Ahmad Khiet <akhiet>
Status: CLOSED CURRENTRELEASE QA Contact: Evelina Shames <eshames>
Severity: high Docs Contact:
Priority: unspecified    
Version: 4.4.1CC: bmarzins, bugs, bzlotnik, dfodor, eshenitz, sfishbai
Target Milestone: ovirt-4.4.5Flags: pm-rhel: ovirt-4.4+
Target Release: 4.4.5   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: ovirt-engine-4.4.5 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-03-18 15:13:40 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:
Attachments:
Description Flags
Screenshot showing that SCSI Pass-Through enabled by default none

Description Nir Soffer 2020-11-12 13:22:33 UTC 
Created attachment 1728783 [details]
Screenshot showing that SCSI Pass-Through enabled by default

Description of problem:

When creating a new Direct LUN disk, "SCSI Pass-Through" is enabled by
default. SCSI Pass-Through is needed only in special cases, is not
supported properly by multipath (see bug 1854659, bug 1855868, bug 1860377)
and it does not provide the best performance.

As a general rule, RHV defaults should give the simplest, most reliable, and
best performance out of the box. Features that are not common or may
decrease reliability or performance should be enabled by a user only if
needed. This gives the best user experience and minimize support cost. 

Version-Release number of selected component (if applicable):
4.4.4.1_master

How reproducible:
Always

Steps to Reproduce:
1. Create new vm or edit an existing vm
2. Create new Direct LUN disk

Actual results:
Enable SCSI Pass-Through is checked

Expected results:
Enable SCSI Pass-Through is not checked

Additional info:
The issue with SCSI Pass-Through and multiapth is explained by bug 1854659.

oVirt does not have any mechanism to resume VMs using Direct LUN disks so
VM paused because of failed ioctl are never resumed automatically. Direct LUN
disks not using SCSI Pass-Through are less likely to get paused because of
ioctl failure.

When creating a floating Direct LUN disk, SCSI Pass-Through is not enabled
by default. The issue exist only when creating attached disk.
Comment 1 Nir Soffer 2020-11-12 13:37:56 UTC 
Benny, do we have the same issue with MBS disks?
Comment 2 Benny Zlotnik 2020-11-12 14:01:56 UTC 
(In reply to Nir Soffer from comment #1)
> Benny, do we have the same issue with MBS disks?

No, we currently do not have the option to enable it (not in the GUI at least)
Comment 3 Evelina Shames 2021-01-28 08:12:24 UTC 
Verified on ovirt-engine-4.4.5.2-0.1.el8ev.
When creating a new VM or editing an existing VM and creating a new Direct LUN disk, 'Enable SCSI Pass-Through' is not checked as expected.

Moving to VERIFIED.
Comment 4 Sandro Bonazzola 2021-03-18 15:13:40 UTC 
This bugzilla is included in oVirt 4.4.5 release, published on March 18th 2021.

Since the problem described in this bug report should be resolved in oVirt 4.4.5 release, it has been closed with a resolution of CURRENT RELEASE.

If the solution does not work for you, please open a new bug report.
Comment 5 Sandro Bonazzola 2021-03-22 12:55:36 UTC 
This bugzilla is included in oVirt 4.4.5 release, published on March 18th 2021.

Since the problem described in this bug report should be resolved in oVirt 4.4.5 release, it has been closed with a resolution of CURRENT RELEASE.

If the solution does not work for you, please open a new bug report.