On RHEL systems, persistent network interface configurations for a specific interface like `ens192` are stored in `/etc/sysconfig/network-scripts/ifcfg-`. The other files are either for a different distribution (/etc/network/interfaces), hostname resolution (/etc/hosts), or non-persistent DNS settings (/etc/resolv.conf).

The correct sequence uses `parted` to create a GPT partition table and a primary partition spanning the entire disk, followed by `mkfs.xfs` to create the XFS filesystem on the new partition (`/dev/sdb1`). Option A uses `fdisk` which is valid but doesn’t specify the partition creation steps. Option C formats the raw disk without a partition, which is not standard practice for a data disk. Option D creates an ext4 filesystem instead of XFS.

The ability to list files (read) but not create new ones (write) in a directory where the user has the necessary directory permissions (755 gives others read and execute) strongly points to the underlying filesystem being full. The `df -h` command shows disk space usage. Running out of inodes (Option A) would give a different error about not being able to create files. The other options describe issues that would prevent listing or accessing the directory altogether.

The `/etc/fstab` file is the correct configuration file for defining filesystems to be mounted automatically at boot. The syntax is: `device mountpoint filesystem-type options dump-fsck-order`. The entry `/dev/vg01/lv_archive /archive xfs defaults 0 0` is correct. `/etc/mtab` is dynamic, `/etc/filesystems` is for filesystem type recognition, and using `rc.local` is a deprecated and less reliable method.

The `nohup` command makes the script immune to hangups (SIGHUP), the `>` redirects standard output to `output.log`, and the `&` runs the job in the background. This combination ensures the script continues after logout and saves output. Option B runs in the foreground and would stop on logout. Option C runs in the foreground. Option D with `screen` is a valid alternative but is not a single command and `screen` may not be installed by default, whereas `nohup` is a core utility.

`top -u jdoe` launches the `top` command filtered to show only processes belonging to the user `jdoe`, updating in real-time and sorted by CPU usage by default. This is the most direct and efficient way. Option A gives a static snapshot. Option C (`htop`) is excellent but not specified in the base RHEL exam objectives. Option D (`vmstat`) shows system-wide statistics, not per-process.

In a `dracut` emergency shell, the most direct fix for a corrupt or missing initramfs is to regenerate it using `dracut –force`. This command recreates the initramfs for the currently running kernel. `mkinitrd` is an older tool. `grub2-mkconfig` rebuilds the bootloader configuration, which is a different problem. `fsck` checks filesystems, which is not the indicated issue.

The crontab format is: `minute hour day-of-month month day-of-week command`. Day-of-week can be 0 or 7 for Sunday. Therefore, `15 2 * * 0` means minute 15, hour 2, any day-of-month, any month, on Sunday. Option B uses `7` for Sunday, which is also valid on many systems, but the RHEL convention and the exam typically use `0`. Option C runs on the 15th day of the month. Option D runs every minute on Sunday.

`journalctl -u custom-app` filters the systemd journal to show all log entries for the `custom-app` unit. This is the primary and most comprehensive method for viewing service-specific logs in RHEL 7/8/9. `systemctl status` shows a brief summary, including the last few log lines. `/var/log/messages` is a general log file and may not contain the specific service output. A service-specific log file (Option D) is not the default for systemd-managed services.

On RHEL systems, persistent network interface configurations for a specific interface like `ens192` are stored in `/etc/sysconfig/network-scripts/ifcfg-`. The other files are either for a different distribution (/etc/network/interfaces), hostname resolution (/etc/hosts), or non-persistent DNS settings (/etc/resolv.conf).0