Bug 2172605

Summary:	ReaR formats all dasds on s390x
Product:	Red Hat Enterprise Linux 8	Reporter:	Pavel Cahyna <pcahyna>
Component:	rear	Assignee:	Pavel Cahyna <pcahyna>
Status:	CLOSED ERRATA	QA Contact:	David Jež <djez>
Severity:	high	Docs Contact:	Šárka Jana <sjanderk>
Priority:	unspecified
Version:	8.5	CC:	djez, ovasik, pcahyna, rhel-cs-system-management-subsystem-qe
Target Milestone:	rc	Keywords:	Triaged
Target Release:	---	Flags:	pm-rhel: mirror+
Hardware:	s390x
OS:	Unspecified
Whiteboard:
Fixed In Version:	rear-2.6-9.el8	Doc Type:	Bug Fix
Doc Text:	.ReaR handles excluded DASDs on the IBM Z architecture correctly Previously on the IBM Z architecture, ReaR reformatted all connected Direct Access Storage Devices (DASD) during the recovery process, including those DASDs that users excluded from the saved layout and did not intend to restore their content. As a consequence, if you excluded some DASDs from the saved layout, their data were lost during system recovery. With this update, ReaR no longer formats excluded DASDs during system recovery, including the device from which the ReaR rescue system was booted (using the zIPL bootloader). You are also prompted to confirm the DASD formatting script before ReaR reformats DASDs. This ensures that the data on excluded DASDs survive a system recovery.	Story Points:	---
Clone Of:	2172589	Environment:
Last Closed:	2023-05-16 08:42:15 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2172589
Bug Blocks:	2130206
Deadline:	2023-02-27

Description Pavel Cahyna 2023-02-22 16:57:22 UTC

+++ This bug was initially created as a clone of Bug #2172589 +++

Description of problem:

The s390x architecture needs some unique handling of disks (called DASDs - Direct Access Storage Devices) during layout restoration. The DASDs need to get formatted (at low level), unless they are formatted already, before they can be partitioned. Formatting of the disks is controlled by the dasdfmt directive in the disklayout.conf file. This directive is emitted for all dasds, regardless of whether they should be included in the layout. While there is component exclusion code that comments out the "disk" lines for unused disks automatically, the dasdfmt lines for unused disks stay in the layout file, which later causes the unused disks to be reformatted unconditionally. Crucially, this includes the disk with the backup (one must use network backup storage because of this). 

As a result, if users have disks that ReaR is not supposed to touch (neither backup not restore), the recovery procedure will erase them.

Version-Release number of selected component (if applicable):
2.6-16.el9 (and anything earlier)

How reproducible:
well reproducible, but needs multiple disks

Steps to Reproduce:
1. get a s390x machine with multiple disks and install RHEL only on one disk (e.g. dasda)
2. partition (fdasd -a) and create a filesystem on the second disk (e.g. dasdb) but do not mount it
3. perform a ReaR backup
4. recover the system with ReaR

Actual results:
Filesystem on dasdb is gone

Expected results:
Filesystem on dasdb should have survived - ReaR does not include dasdb in the recreated layout as it is not used (filesystem is not mounted).

Comment 10 errata-xmlrpc 2023-05-16 08:42:15 UTC

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 (rear bug fix and enhancement update), 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://access.redhat.com/errata/RHBA-2023:2900