--- title: "Mount an AWS EBS Disk on Ubuntu | Ameya Shenoy" description: "Partition and format a new AWS EBS volume, mount it on Ubuntu with a filesystem UUID and fstab, and configure ownership with practical safety checks." canonical: "https://www.codingcoffee.dev/blog/aws-mount-disk" published: "2026-10-14" tags: "notes" --- # Mount a Disk on AWS By Ameya Shenoy · Published 2026-10-14 Partition and format a new AWS EBS volume, mount it on Ubuntu with a filesystem UUID and fstab, and configure ownership with practical safety checks. A quick reference for mounting a **new, empty EBS volume** on an Ubuntu EC2 instance at `/mnt/data`. Attach the volume to the instance from the AWS console or API first. The EBS volume and instance must be in the same Availability Zone. These commands assume the attached disk is `/dev/nvme1n1` and the login user is `ubuntu`; check both before proceeding. **Partitioning and formatting can destroy existing data. Do not run these steps on the root disk or a volume containing data you want to keep.** For an existing filesystem, skip partitioning and formatting, identify its UUID and mount it instead. Take an EBS snapshot before modifying a volume with valuable data. ## 1. Identify the disk ```sh lsblk -o NAME,SIZE,FSTYPE,UUID,MOUNTPOINTS,MODEL,SERIAL ``` Check the size, existing filesystems and mount points. On Nitro-based EC2 instances, EBS volumes appear as NVMe devices, so the device name can differ from the name supplied when attaching the volume. Use the EBS volume ID in the NVMe serial number to confirm which disk you are working on; do not assume `nvme1n1` is always the data disk. The root filesystem is mounted at `/`, possibly through another block-device layer. Leave its backing disk alone. If the intended disk already has partitions or a filesystem, stop and inspect it before changing anything. ## 2. Create a partition ```sh sudo gdisk /dev/nvme1n1 ``` `gdisk` edits the disk's GPT partition table. For a new, empty disk: - Enter `n` to create a partition. - Accept the default partition number, first sector and last sector to create partition `1` using the available space. - Accept the default `8300` type code for a Linux filesystem. - Enter `p` to review the proposed partition table. - Enter `w` and confirm only after checking that you selected the correct disk. Changes are written when you confirm `w`. The resulting partition should appear as `/dev/nvme1n1p1`: ```sh lsblk /dev/nvme1n1 ``` The disk is `/dev/nvme1n1`; `p1` identifies its first partition. A filesystem can also live directly on an entire EBS device, but this note uses a partitioned layout. ## 3. Create an ext4 filesystem ```sh sudo mkfs.ext4 /dev/nvme1n1p1 ``` A partition defines a region of the disk; a filesystem gives that region the structures needed to store files and directories. `mkfs.ext4` creates those structures and assigns a filesystem UUID. **Run this only on the new, empty partition.** Formatting is not a mounting command and must not be repeated each time you attach or reboot the instance. ## 4. Configure a persistent mount Read the UUID after formatting: ```sh lsblk -f /dev/nvme1n1 sudo blkid /dev/nvme1n1p1 ``` Use the **filesystem UUID of `/dev/nvme1n1p1`**, not the EBS volume ID or `PARTUUID`. A UUID lets Linux find the filesystem even if its NVMe device name changes. Back up the mount configuration, then edit it: ```sh sudo cp /etc/fstab /etc/fstab.backup sudo vim /etc/fstab ``` Add this line, replacing `` with the actual UUID, without angle brackets: ```text UUID= /mnt/data ext4 defaults,nofail,x-systemd.device-timeout=10s 0 2 ``` `/etc/fstab` describes filesystems to mount at boot. The fields mean: - `UUID=...`: the filesystem to mount. - `/mnt/data`: the directory where its contents will appear. - `ext4`: the filesystem type created in the previous step. - `defaults`: the usual mount options, including read-write access and automatic mounting. - `nofail`: allow boot to continue if this optional data volume cannot be mounted. - `x-systemd.device-timeout=10s`: limit how long systemd waits for the device to appear to 10 seconds. This is not a timeout for the entire mount operation. - `0`: disable the legacy `dump` backup flag for this filesystem. - `2`: enable boot-time filesystem checks after the root filesystem, which normally uses `1`. `nofail` is useful for an optional disk, but it is not a guarantee that applications can safely run without it. A service writing to `/mnt/data` while the volume is absent could write to the root disk instead. Services that require this volume should have an explicit mount dependency, such as `RequiresMountsFor=/mnt/data` in their systemd unit. ## 5. Create the mount point and mount the disk ```sh sudo mkdir -p /mnt/data sudo systemctl daemon-reload sudo mount -a findmnt --mountpoint /mnt/data ``` `mkdir -p` creates the directory where the filesystem will be attached. Keep it empty: mounting over existing files hides them until the volume is unmounted, rather than moving them onto the volume. `systemctl daemon-reload` tells systemd to reload its configuration and rerun its generators, including the one that turns `fstab` entries into mount units. It does not mount the filesystem by itself. `mount -a` attempts to mount the eligible entries in `/etc/fstab`, including the new one. It also processes other entries, so investigate any reported errors before rebooting. `findmnt --mountpoint /mnt/data` verifies that this exact directory is a mount point. Confirm that its source is the expected partition and its filesystem type is `ext4`. If the mount failed, fix the UUID, mount options or device availability before proceeding. ## 6. Give the Ubuntu user ownership Only after confirming that the disk is mounted: ```sh sudo chown -R ubuntu:ubuntu /mnt/data/ ``` A freshly created ext4 filesystem is owned by `root`. This command changes ownership of the mounted directory and everything beneath it to the `ubuntu` user and group, allowing that user to write without `sudo`. For a new disk, this is convenient. On a populated disk, `-R` can be slow and overwrite ownership required by other users or services. If only the top-level directory needs to change, use `sudo chown ubuntu:ubuntu /mnt/data` instead. Use the application's actual user and group for a service-owned volume. Finally, check the mounted filesystem's capacity: ```sh df -h /mnt/data ``` The volume is now mounted and configured to mount again at boot. After a planned reboot, verify it again with `findmnt --mountpoint /mnt/data` before relying on it. --- Canonical page: https://www.codingcoffee.dev/blog/aws-mount-disk [Site guide](/llms.txt) · [Contact](/contact) · [Sitemap](/sitemap-index.xml)