Add volume storage to a Fly Launch app

• How Fly Volumes work
• How to manage volumes with flyctl commands
• How to manage volume snapshots (backups)

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Launch a new app with a Fly Volume

1. Launch a new app from your project source directory with the --no-deploy option so it doesn’t deploy automatically. Include any required options for deploying your app, like --image or --dockerfile.
   fly launch --no-deploy
   
   fly launch creates a fly.toml app configuration file in your project source directory.
2. After the app is created, add a [mounts] section in the fly.toml, where source is the volume name and destination is the directory where the volume should be mounted on the Machine file system. For example:
   [mounts]
     source = "myapp_data"
     destination = "/data"
   
   Note: You can’t mount a volume with destination="/" since / is used for the root file system.
3. Deploy the app:
   fly deploy 
   
4. Confirm that the volume is attached to a Machine.
5. (Recommended only if your app handles replication) Clone the first Machine to scale out to two Machines with volumes:
   fly machine clone <machine id>
   
   List volumes to check the result:
   fly volumes list
   
   Example output showing two volumes with attached Machines:
   ID                      STATE   NAME    SIZE    REGION  ZONE    ENCRYPTED       ATTACHED VM     CREATED AT     
   vol_ez1nvxkwl3jrmxl7    created data    1GB     lhr     4de2    true            91851edb6ee983  39 seconds ago
   vol_zmjnv8m81p5rywgx    created data    1GB     lhr     b6a7    true            5683606c41098e  7 minutes ago
   

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Add volumes to an existing app

1. Add a [mounts] section in the app’s fly.toml, where source is the volume name and destination is the directory where the volume should be mounted on the Machine file system. For example:
   [mounts]
     source = "myapp_data"
     destination = "/data"
   
2. Run fly status to check the regions of the Machines and then create the volume in the same regions as your app’s Machines. For example:
   fly volumes create <volume name> -r <region code>
   
3. Repeat step 2 for each Machine in the process group. If you create an app using the fly launch command, then the app will usually have two Machines in the app process by default.
   Note: If you have multiple Machines, then you need to create an equal number of volumes with the same name. For example, your app’s [mounts] config specifies source="myapp_data" and you have three Machines in bos (Boston), then you need to create three volumes named myapp_data in bos. Every volume has a unique ID to allow for multiple volumes with the same name.
4. Deploy the app:
   fly deploy 
   
5. Confirm that the volume is attached to a Machine.

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Confirm the volume is attached to a Machine

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List the Machines

fly machine list

1 machines have been retrieved from app my-app-name.
View them in the UI here

my-app-name
ID            	NAME        STATE   REGION	 IMAGE                	IP ADDRESS                    	VOLUME              	CREATED             	LAST UPDATED        	APP PLATFORM	PROCESS GROUP	SIZE
328773d3c47d85	my-app-name	stopped	yul   	flyio/myimageex:latest	fdaa:2:45b:a7b:19c:bbd4:95bb:2	vol_6vjywx86ym8mq3xv	2023-08-20T23:09:24Z	2023-08-20T23:16:15Z	v2          	app          	shared-cpu-1x:256MB

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List the volumes

fly volumes list

ID                      STATE   NAME    SIZE    REGION  ZONE    ENCRYPTED       ATTACHED VM     CREATED AT    
vol_zmjnv8m81p5rywgx    created data    1GB     lhr     b6a7    true            5683606c41098e  3 minutes ago

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SSH into the Machine

fly ssh console -s -C df

? Select VM: lhr: 5683606c41098e fdaa:0:3b99:a7b:7e:3155:9844:2 nameless-feather-6339
Connecting to fdaa:0:3b99:a7b:7e:3155:9844:2... complete
Filesystem     1K-blocks   Used Available Use% Mounted on
devtmpfs          103068      0    103068   0% /dev
/dev/vda         8191416 172748   7582856   3% /
shm               113224      0    113224   0% /dev/shm
tmpfs             113224      0    113224   0% /sys/fs/cgroup
/dev/vdb         1011672   2564    940500   1% /data

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Access a volume

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Related topics

• Fly Volumes overview
• mounts section in the fly.toml app configuration file
• Create and manage volumes
• Manage volume snapshots
• Scale an app with volumes