I get a write permission error yet the back completes fully.  Jenkins definitely has access to the backup folder (logging in as jenkins I can write to the folder).  In this installation jenkins is in the vboxsf group.

 
Apr 04, 2024 8:04:07 AM INFO org.jvnet.hudson.plugins.thinbackup.ThinBackupMgmtLink doBackupManual
Starting manual backup.
Apr 04, 2024 8:04:08 AM INFO org.jvnet.hudson.plugins.thinbackup.backup.HudsonBackup backupJobsDirectory
Found 12 jobs in /var/lib/jenkins/jobs to back up.
Apr 04, 2024 8:07:18 AM SEVERE org.jvnet.hudson.plugins.thinbackup.ThinBackupPeriodicWork backupNow
Cannot perform a backup. Please be sure Jenkins has write privileges in the configured backup path '/media/sf_OneDrive/jenkins_backup'. java.nio.file.FileSystemException: /media/sf_OneDrive/jenkins_backup/FULL-2024-04-02_20-00/com.cloudbees.hudson.plugins.folder.config.AbstractFolderConfiguration.xml: Operation not permitted at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:100) at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111) at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116) at java.base/sun.nio.fs.UnixFileSystemProvider.implDelete(UnixFileSystemProvider.java:249) at java.base/sun.nio.fs.AbstractFileSystemProvider.deleteIfExists(AbstractFileSystemProvider.java:110) at java.base/java.nio.file.Files.deleteIfExists(Files.java:1181) at org.apache.commons.io.file.PathUtils.deleteFile(PathUtils.java:487) at org.apache.commons.io.file.PathUtils.delete(PathUtils.java:392) at org.apache.commons.io.FileUtils.forceDelete(FileUtils.java:1341) Caused: java.io.IOException: Cannot delete file: /media/sf_OneDrive/jenkins_backup/FULL-2024-04-02_20-00/com.cloudbees.hudson.plugins.folder.config.AbstractFolderConfiguration.xml at org.apache.commons.io.FileUtils.forceDelete(FileUtils.java:1344) at org.apache.commons.io.FileUtils.cleanDirectory(FileUtils.java:324) Caused: org.apache.commons.io.IOExceptionList: /media/sf_OneDrive/jenkins_backup/FULL-2024-04-02_20-00 at org.apache.commons.io.FileUtils.cleanDirectory(FileUtils.java:331) at org.apache.commons.io.FileUtils.deleteDirectory(FileUtils.java:1192) at org.jvnet.hudson.plugins.thinbackup.backup.BackupSet.delete(BackupSet.java:190) at org.jvnet.hudson.plugins.thinbackup.backup.HudsonBackup.removeSuperfluousBackupSets(HudsonBackup.java:624) at org.jvnet.hudson.plugins.thinbackup.backup.HudsonBackup.backup(HudsonBackup.java:218) at org.jvnet.hudson.plugins.thinbackup.ThinBackupPeriodicWork.backupNow(ThinBackupPeriodicWork.java:90) at org.jvnet.hudson.plugins.thinbackup.ThinBackupMgmtLink$1.execute(ThinBackupMgmtLink.java:84) at hudson.model.AsyncPeriodicWork.lambda$doRun$0(AsyncPeriodicWork.java:102) at java.base/java.lang.Thread.run(Thread.java:829)