Find, format, and mount an AWS Ephemeral NVMe disk within ec2 in user data

mount_aws_nvme_ephemeral.sh

#!/usr/bin/env bash


###
## This mounts a (single) ephemral NVMe drive in an EC2 server.
## It's meant to be run once, within user-data
## For EBS drives (non-ephemeral storage), see: https://gist.github.com/jalaziz/c22c8464cb602bc2b8d0a339b013a9c4
#


# Install the "nvme" command
# See: https://github.com/linux-nvme/nvme-cli
sudo apt-get install -y nvme-cli


# Create a mount point (directory)
sudo mkdir -p /some/mount


# Find ephemeral storage (assumes a single ephemeral disk)
# and format it (assumes this is run on first-boot in user-data, so the disk is not formatted)
EPHEMERAL_DISK=$(sudo nvme list | grep 'Amazon EC2 NVMe Instance Storage' | awk '{ print $1 }')
sudo mkfs.ext4 $EPHEMERAL_DISK
sudo mount -t ext4 $EPHEMERAL_DISK /some/mount


### For some crazy reason, add ephemeral disk mount to /etc/fstab
## even tho you lose data in stop/starts of ec2 (I believe you keep the data via regular reboots?)
#
# Find the mounted drive UUID so we can mount by UUID
EPHEMERAL_UUID=$(sudo blkid -s UUID -o value $EPHEMERAL_DISK)
echo "UUID=$EPHEMERAL_UUID /opt/nomad ext4 defaults 0 0" | sudo tee -a /etc/fstab

that’s correct, yep!

…

On Thu, Mar 2, 2023 at 06:26 Rob ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ Thanks, really convenient script! Although I'm just wondering where /opt/nomad on line 32 came from? echo "UUID=$EPHEMERAL_UUID /opt/nomad ext4 defaults 0 0" | sudo tee -a /etc/fstab I assumed you should use your mount point there, /some/mount? — Reply to this email directly, view it on GitHub <https://gist.github.com/40f7807920aa1198fa07b9e69dc82b56#gistcomment-4489223> or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADSDU6D6KSHVZHETAE3MGLW2B7VPBFKMF2HI4TJMJ2XIZLTSKBKK5TBNR2WLJDHNFZXJJDOMFWWLK3UNBZGKYLEL52HS4DFQKSXMYLMOVS2I5DSOVS2I3TBNVS3W5DIOJSWCZC7OBQXE5DJMNUXAYLOORPWCY3UNF3GS5DZVRZXKYTKMVRXIX3UPFYGLK2HNFZXIQ3PNVWWK3TUUZ2G64DJMNZZDAVEOR4XAZNEM5UXG5FFOZQWY5LFVEYTANJZGQ2TENRWU52HE2LHM5SXFJTDOJSWC5DF> . You are receiving this email because you authored the thread. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .

ec2 instance will stuck if you use uuid in /etc/fstab after stop/start.
I added some checks. If I need to save data after a reboot, I will check if it's formatted

MOUNT="/opt/data"
EPHEMERAL_DISK=\$(sudo nvme list | grep 'Amazon EC2 NVMe Instance Storage' | awk '{ print \$1 }')
# Check if the mount point exists in /proc/mounts
if grep -qs \${MOUNT} /proc/mounts; then
    echo "It's mounted."
else
    # Check if the block device exists and is not formatted as ext4
    if [ -b \${EPHEMERAL_DISK} ] && ! blkid \${EPHEMERAL_DISK} | grep -qs ext4; then
        echo "It's not mounted and not formatted, formatting..."
        # Format the block device as ext4
        if mkfs.ext4 \${EPHEMERAL_DISK}; then
            echo "Formatting \${EPHEMERAL_DISK} success!"
        else
            echo "Failed to format \${EPHEMERAL_DISK}."
            exit 1
        fi
    fi
    
    # Attempt to mount the block device to the specified mount point
    echo "It's not mounted, trying to mount..."
    if mkdir -p \${MOUNT} && mount -t ext4 \${EPHEMERAL_DISK} \${MOUNT}; then
        echo "Mount \${MOUNT} success!"
    else
        echo "Something went wrong with the mount - \${EPHEMERAL_DISK}"
        exit 1
    fi
fi

Thanks for sharing!