Formatting and Partitioning Drives in elementary OS With Disk Utility

When you plug a new SSD or external hard drive into a machine running elementary OS, the system happily mounts it for light browsing but never gives you proper control over how that drive is laid out. If the volume shows up with a weird capacity, refuses to read properly, or needs to be repurposed for a different job, the built-in tool for handling all of that is Disk Utility. Knowing how to drive it saves the cost of buying another drive at JB Hi-Fi or Officeworks when the one already sitting on your desk could be wiped clean and put back to work.

Disk Utility sits quietly inside the application menu under the name "Disks" and is actually the gnome-disks package shipped with the Pantheon desktop. It handles partition tables, formatting, mounting, SMART health checks, benchmark runs, and even the creation of encrypted volumes, all from a single window. Before any of this gets touched, it helps to know which disk is which, especially in laptops that mix an NVMe boot drive with a SATA SSD and an SD card slot, a fairly common setup in stores like those in Sydney's Broadway or Melbourne's Box Hill.

Getting to Know Disk Utility in elementary OS

The first launch reveals a clean three-pane layout. On the left, every recognised storage device is listed, including internal disks, USB sticks, SD cards, and any optical media. The top-right corner houses a hamburger menu that opens additional actions like creating disk images, restoring images, and benchmarking sequential reads and writes. The largest pane on the right shows a visual map of the selected drive, with each partition drawn as a coloured block proportional to its size.

Clicking the gears icon on a partition unlocks the day-to-day operations: format, edit mount options, encrypt, delete, and resize. The "Format Disk" option at the top of the screen wipes the entire device and installs a fresh partition table, which is the step that decides whether the drive will play nicely with other operating systems. The "Edit Partition" option only changes a single slice without touching the rest of the disk.

Before formatting or partitioning anything, look at the drive's model number, capacity, and serial in the top half of the window. Linux assigns device names like /dev/sda, /dev/sdb, /dev/nvme0n1, and so on, in the order that the kernel detected them. A USB drive booted on a different port can suddenly claim the /dev/sda label from the internal NVMe, which is why the visual map and the model information are worth a slow glance. A recovery job on the wrong disk is the fastest way to lose a holiday's worth of RAW photos from a trip up the coast.

Backing Up Before You Change Partitions

Once the right drive is identified, the next step is to copy anything important somewhere else. elementary OS's default file manager, Files, supports drag-and-drop copying, but for anything larger than a few gigabytes, a dedicated backup tool is more reliable. Timeshift is the standard option in the elementary ecosystem for system snapshots, and a Timeshift-based backup routine keeps the root filesystem safe while user data sits on a separate partition. For files in the home folder, a manual copy to another drive or a quick rsync run is usually enough.

Australians replacing an aging spinning drive in an older MacBook or ThinkPad often have a mix of Time Machine images, Lightroom catalogues, and tax records stored on the same disk. Those need to be copied somewhere else before any table changes, since writing a new partition table reads the first few megabytes of the device and ignores everything after. Brisbane-based photographers running dual-boot setups frequently keep a working copy on a portable SSD during shoot weeks, which makes the loss of an internal drive an inconvenience rather than a catastrophe.

If the disk being modified is small, under 32 GB, a simple verification that nothing else is mounted from it is enough. For multi-terabyte drives, SMART data viewed from the Drive menu offers a quick health read. A drive reporting reallocated sectors or a high temperature warning should not be repartitioned, because a failed sector during the table write can leave the device in a partially initialised state that even Disk Utility struggles to recover.

Creating a Partition Table That Fits Your Needs

A partition table is a small piece of metadata at the very start of the drive that tells the operating system where one partition ends and the next begins. The two modern options in Disk Utility are Master Boot Record and GUID Partition Table. MBR is fine for USB sticks and drives under 2 TB that only need to work on legacy hardware, while GPT is the right pick for anything larger or anything that will boot an operating system in UEFI mode.

elementary OS itself boots from a GPT-formatted drive with a small EFI System Partition, a root partition formatted ext4, and a swap area. Replicating that layout on a second drive does not require the EFI partition unless the second drive is going to boot the system, but keeping the root and swap structure makes for a tidy mirror that can be cloned with a single dd command if disaster strikes later.

Selecting "Format Disk" from the toolbar opens a confirmation dialogue that lists the chosen device by name and capacity, asks whether to use MBR or GPT, and then asks to confirm by typing the device path or pressing a button depending on the version. There is no undo beyond restoring from a backup, so the visual map on the right pane should match the device in hand: if it shows a 1 TB drive with no partitions, that is the one that is about to be wiped. Otherwise, double-check the model number against the printed label on the external casing.

Choosing the Right Filesystem for Your Drive

After the partition table is in place, each new slice gets its own format choice. Disk Utility supports FAT32, exFAT, NTFS, ext4, and a few others through the Linux kernel. FAT32 is the universal option for USB sticks that need to plug into older Windows machines, karaoke machines, or the consoles in family rooms around suburban Adelaide and Perth. The catch is a 4 GB single-file limit, which makes it useless for anything beyond documents and small videos.

exFAT removes the 4 GB ceiling and keeps broad compatibility with modern Windows and macOS. It is often the best pick for portable drives that travel between an elementary OS laptop at home and a Windows desktop at the office. Performance is good enough for video editing off a SATA SSD, and the licence is now settled enough that Linux's in-tree driver is stable. NTFS is the right choice when the drive spends most of its life attached to a Windows machine and is only occasionally mounted on elementary, since the read-write support has improved but still hits the occasional permission issue.

For drives that live exclusively on Linux machines, ext4 is the dependable default. Mature, fast, and supported by every rescue distribution in case of a broken boot, ext4 is what the elementary installer uses for its root filesystem. Power users sometimes pick btrfs for snapshots, but btrfs on a single disk without redundancy does not add much beyond complexity, so it is reserved here for users who already understand its quirks.

A quick reference for picking the right match:

Once the format is decided, the File System drop-down inside the Format dialogue handles the rest, including volume name and whether to wipe existing signatures before writing the new one.

Mounting, Labels, and Optional Encryption

A formatted partition is invisible to the file manager until it has a mount point and, ideally, a friendly label. Disk Utility's mount options panel lets a user pick the default mount point, choose whether the partition should appear in the sidebar, and decide if it should be mounted at boot. Setting "Mount at startup" is useful for a drive dedicated to project files, while leaving it off is safer for USB sticks that might be yanked mid-write.

Renaming a partition to something like "Work-2024" or "Holidays-2023" goes a long way when several drives are plugged into a hub on a desk in Adelaide or Canberra. Labels also help identify the right device in command-line tools, where /dev/disk/by-label/Work-2024 is far harder to mix up than /dev/sdc1. For drives that travel, the LUKS encryption option inside Disk Utility protects the contents with a passphrase prompt at first mount, which is a calmer substitute for carrying a drive across the country without worrying about loss.

Encrypted volumes look like any other partition after the passphrase is entered, but the underlying encryption is handled transparently by the kernel. Performance on SSDs is negligible, while on spinning disks it can shave a few percent off sequential reads. The recovery story, however, is far better than for a plain partition that has been wiped: even a partially overwritten ext4 filesystem can be coaxed back through photorec or testdisk, but a wiped LUKS header is effectively gone.

Fixing Common Problems and Recovering Lost Space

A frequent surprise on a freshly formatted drive is that the capacity shown in Files is smaller than advertised. A 2 TB drive reports as 1.82 TiB, which is normal because manufacturers use decimal prefixes and the operating system reads binary. Anything larger than that gap means the partition is misaligned or the table is older than expected. Running a "Check" and a "Repair" from the drive menu fixes most mismatches without losing data.

Another classic issue is a USB stick that suddenly turns read-only because the kernel detected filesystem errors and remounted it protectively. A reformat through Disk Utility clears the dirty flag and brings write access back. The same trick revives SD cards that have been retired from a camera but appear locked when plugged into a card reader in the home office.

If a partition edit goes wrong, the GParted live USB can pick up drives that Disk Utility refuses to touch. Booting from the USB gives a slightly heavier interface, yet it can move, resize, or restore partitions that elementary's own tool refuses to alter in place. Keeping a small rescue stick with GParted handy is a healthy habit for any Australian household that relies on Linux for backups, and the cost is around the price of a takeaway coffee in Melbourne or Hobart.

Take an evening this week, identify the spare drive sitting in a drawer, plug it in, and walk it through a GPT table followed by an ext4 partition labelled with a name that actually means something. Once it is mounted, drag a folder of important files onto it and confirm that the copy matches the original by checksum. The whole routine takes about ten minutes, and the result is a tidy, ready-to-go volume that will earn its keep the next time a backup is needed.