Bug 1946911

Summary:	Provide a way to exclude multipath devices from being scanned
Product:	Red Hat Enterprise Linux 8	Reporter:	Renaud Métrich <rmetrich>
Component:	rear	Assignee:	Pavel Cahyna <pcahyna>
Status:	CLOSED MIGRATED	QA Contact:	CS System Management SST QE <rhel-cs-system-management-subsystem-qe>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	8.3	CC:	ovasik, pcahyna
Target Milestone:	rc	Keywords:	MigratedToJIRA
Target Release:	---	Flags:	pm-rhel: mirror+
Hardware:	All
OS:	Linux
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Last Closed:	2023-09-21 23:40:32 UTC	Type:	Bug
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description Renaud Métrich 2021-04-07 08:39:37 UTC

Description of problem:

Currently all block devices found in /sys/block are scanned, which makes the creation of the ReaR recovery be super slow when having tons of multipath devices.
I'm proposing to backport PR https://github.com/rear/rear/pull/2597 to avoid the scan.

On some systems, it saves up to 40 minutes!

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

rear-2.4 / rear-2.6


How reproducible:

N/A

Comment 1 Pavel Cahyna 2021-04-07 09:36:39 UTC

Is there any relation to the existing AUTOEXCLUDE_MULTIPATH variable ("y" by default)?

Comment 2 Renaud Métrich 2021-04-07 09:55:53 UTC

Somehow yes.
The issue is that the code (for now) collects everything about devices, then later excludes devices.
Changing the current code to do the opposite is extremely complicated.

Comment 3 Pavel Cahyna 2021-04-08 09:25:34 UTC

Can you please attach a log of the problematic "rear mkrescue" that shows the 40 minute slowdown? I would like to check whether the SCSI devices are detected correctly as paths of the multipath devices or not. (If not, then the slowdown might be caused by this and the best solution would be to fix the detection.)

Comment 9 RHEL Program Management 2023-09-21 23:35:29 UTC

Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug.

Comment 10 RHEL Program Management 2023-09-21 23:40:32 UTC

This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there.

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