The correct first step is to identify the source of the space consumption. `du -sh /var/* | sort -rh | head -10` provides a safe, read-only overview of the largest directories under `/var`, allowing for informed decisions. Deleting files blindly, resizing partitions, or checking for deleted file handles are actions to take *after* diagnosis and could be destructive or unnecessary.

The error is due to the lack of execute (`x`) permission. `chmod +x` adds the execute permission for the user, group, and others based on the existing read masks, which is the standard and secure way to make a script executable. `chmod 777` is overly permissive and insecure. Changing ownership or using ACLs doesn’t address the missing execute bit.

`systemctl enable` configures the service to start at boot. `systemctl start` starts the service immediately for the current session. This two-step process is the standard systemd method for both enabling autostart and managing runtime state. `chkconfig` and `service` are legacy SysVinit commands, not native systemd. Masking prevents a service from being started at all.

`fdisk` is a common tool for managing MBR partition tables. The sequence `n` (new), `p` (primary), `1` (partition number 1), and pressing Enter twice to accept the default first and last sectors will create a partition using the entire disk. `mkfs` creates a filesystem *on a partition*, not a raw disk. `parted` can also do this but the command shown only creates a label. `mount` is for mounting an existing filesystem.

`ss -tlnp` shows all TCP (`-t`) sockets that are listening (`-l`), displays port numbers numerically (`-n`), and shows the associated process (`-p`). Piping to `grep :8080` filters for that specific port, confirming if a process is listening there. `ping` uses ICMP, not TCP ports. `netstat -r` shows the routing table. `iptables -L` shows firewall rules, not active connections.

The `-A` (After) flag in `grep` prints the specified number of lines *after* the matching line. `-B` (Before) prints lines before the match. `-C` (Context) prints lines both before and after. `-v` inverts the match, showing lines that do *not* contain the pattern.

The `/etc/group` file contains the list of groups and their members. You would look for the line starting with `sudo:` to see which users are members of the `sudo` group. `/etc/passwd` lists users and their primary groups. `/etc/sudoers` defines sudo rules but not direct group membership lists. `/etc/shadow` stores encrypted passwords.

`crontab -l -u root` lists the cron table for the specific root user, which is where user-specific cron jobs are stored. `/etc/crontab` is the system-wide crontab file, which has a different format. `/etc/cron.d/` contains additional system cron files. `systemctl list-timers` lists systemd timers, not cron jobs.

`rsync -avz` is ideal: `-a` (archive mode) preserves permissions, ownership, timestamps, and copies recursively; `-v` gives verbose output; `-z` compresses data during transfer. A trailing slash on the source (`html/`) copies the *contents* of the directory to the target location. `scp -r` does not reliably preserve all metadata. The `cp` command is for local copies only.

The correct first step is to identify the source of the space consumption. `du -sh /var/* | sort -rh | head -10` provides a safe, read-only overview of the largest directories under `/var`, allowing for informed decisions. Deleting files blindly, resizing partitions, or checking for deleted file handles are actions to take *after* diagnosis and could be destructive or unnecessary.0