What were you trying to do that didn't work?

I was attempting to create a backup using ReaR (Relax-and-Recover) on a Red Hat Enterprise Linux 8 (RHEL 8) system that includes LUKS-encrypted partitions and UEFI boot configuration. The backup process fails during the unmounting step due to a "device or resource busy" error related to an EFI boot image, preventing the backup from completing successfully.

We are manually setting TMPDIR in /etc/rear/local.conf with the following configuration:

export "TMPDIR=/var/tmp/"
This is necessary because the existing /tmp/ directory (as well as other directories outside of /var/) is mounted with the noexec option, and due to security policies, we cannot change this setting to allow execution in /tmp/.

Please provide the package NVR for which bug is seen:

• Package Name: rear
• Version: 2.6
• Release: Relax-and-Recover 2.6 / 2020-06-17
• Architecture: x86_64

How reproducible:

The issue is consistently reproducible in the described environment.

Steps to reproduce

1. Set up a RHEL 8 system with ReaR (version 2.6) installed.
2. Configure ReaR to use TMPDIR=/var/tmp/ in /etc/rear/local.conf due to security policies enforcing noexec on /tmp/ and other directories.
3. Configure ReaR to create a backup, focusing on a system with UEFI and LUKS-encrypted partitions.
4. Run the ReaR backup process using the command:

sudo rear -v mkbackup

1. Observe the backup process, particularly during the step where ReaR attempts to unmount temporary directories.

Expected results

ReaR should successfully unmount all temporary directories and complete the backup process without errors.

Actual results

The backup process fails with the following error:

 
{{umount.nfs: /var/tmp/rear.<session_id>/outputfs: device is busy
Forced unmount of '/var/tmp/rear.<session_id>/outputfs' failed.}}
Additionally, the logs indicate:

 
Broken symlink '/etc/grub2.cfg' in recovery system because 'readlink' cannot determine its link target
ReaR attempts to clean up and delete temporary files and directories after detecting the error, preventing any manual intervention to correct the unmount issue.

Additional Information:

• The issue involves an EFI boot image mounted during the ReaR process.
• LUKS-encrypted partitions and UEFI setup may be contributing factors.
• There is no effective workaround as manual unmounting is not possible after ReaR attempts cleanup.
• The TMPDIR has been manually set to /var/tmp/ to comply with security policies that enforce noexec on /tmp/ and other directories.