WAL-G storage configuration

WAL-G can store backups in S3, Google Cloud Storage, Azure, Swift, remote host (via SSH) or local file system.


To connect to Amazon S3, WAL-G requires that this variable be set:

  • WALG_S3_PREFIX (e.g. s3://bucket/path/to/folder) (alternative form WALE_S3_PREFIX)

WAL-G determines AWS credentials like other AWS tools. You can set AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY (optionally with AWS_SESSION_TOKEN), or ~/.aws/credentials (optionally with AWS_PROFILE), or you can set nothing to fetch credentials from the EC2 metadata service automatically.

Optional variables

  • AWS_ROLE_ARN (e.g. arn:aws:iam::123123123123:role/s3_access)

Set this variable along with AWS_ROLE_SESSION_NAME if you are using AWS IAM roles to access S3 buckets.


Specifies the name to attach to the role session. Useful only when AWS_ROLE_ARN is set.

  • AWS_REGION (e.g. us-west-2)

WAL-G can automatically determine the S3 bucket's region using s3:GetBucketLocation, but if you wish to avoid this API call or forbid it from the applicable IAM policy, specify this variable.


Overrides the default hostname to connect to an S3-compatible service. i.e, http://s3-like-service:9000


To enable path-style addressing (i.e., http://s3.amazonaws.com/BUCKET/KEY) when connecting to an S3-compatible service that lack of support for sub-domain style bucket URLs (i.e., http://BUCKET.s3.amazonaws.com/KEY). Defaults to false.


To configure the S3 storage class used for backup files, use WALG_S3_STORAGE_CLASS. By default, WAL-G uses the "STANDARD" storage class. Other supported values include "STANDARD_IA" for Infrequent Access and "REDUCED_REDUNDANCY" for Reduced Redundancy.


To enable S3 server-side encryption, set to the algorithm to use when storing the objects in S3 (i.e., AES256, aws:kms).


If using S3 server-side encryption with aws:kms, the KMS Key ID to use for object encryption.


To configure AWS KMS key for client-side encryption and decryption. By default, no encryption is used. (AWS_REGION or WALG_CSE_KMS_REGION required to be set when using AWS KMS key client-side encryption)


To configure AWS KMS key for client-side encryption and decryption. By default, no encryption is used. (AWS_REGION or WALG_CSE_KMS_REGION required to be set when using AWS KMS key client-side encryption)


Set to TRUE to allow wal-g in case of network problems to continue downloading from the point that was already downloaded using HTTP Range query. This option is useful when download big files more than few hours.


If WALG_S3_RANGE_BATCH_ENABLED enabled, wal-g will try to reconnect N times, by default 10 times


By default, WAL-G uses ListObjectsV2 to fetch S3 storage folder listings. However, some S3-compatible storages may not support it. Set this setting to true to use ListObjects instead.


Overrides the default request retry limit while interacting with S3. Default is 15.


To store backups in Google Cloud Storage, WAL-G requires that this variable be set:

  • WALG_GS_PREFIX to specify where to store backups (e.g. gs://x4m-test-bucket/walg-folder)

WAL-G determines Google Cloud credentials using application-default credentials like other GCP tools. You can set GOOGLE_APPLICATION_CREDENTIALS to point to a service account json key from GCP. If you set nothing, WAL-G will attempt to fetch credentials from the GCE/GKE metadata service.

Optional variables


Default: 1 hour.


Controls the trimming of extra slashes in paths. The default is true. To allow restoring from WAL-E archives on GCS, set it to false and keep double slashes in WALG_GS_PREFIX values.


To configure GCS Customer Supplied Encryption Key (CSEK) for client-side encryption and decryption. By default, Google-managed keys are used. CSEK must be a 32-byte AES-256 key, encoded in standard Base64.

  • GCS_MAX_CHUNK_SIZE (e.g. 16777216)

Overrides the default maximum chunk size of 52428800 bytes (50 MiB). The size of the chunk must be specified in bytes. This parameter could be useful for different types of uploading (e.g. 16777216 (16MiB) would be perfect for wal-push, 52428800 (50MiB) is suitable for backup-push).

  • GCS_MAX_RETRIES (e.g. 1)

Overrides the default upload and download retry limit while interacting with GCS. Default: 16.


To store backups in Azure Storage, WAL-G requires that these variables be set:

  • WALG_AZ_PREFIX to specify where to store backups in Azure storage (e.g. azure://test-container/walg-folder)

  • AZURE_STORAGE_ACCOUNT to specify the storage account of your backups

WAL-G determines Azure Storage credentials using the azure default credential chain. You can set the standard AZURE_CLIENT_ID/AZURE_TENANT_ID/AZURE_CLIENT_SECRET environment variables to authenticate, or exclude them all if you are using a Managed Identity.

Alternatively, you can set AZURE_STORAGE_ACCESS_KEY to authenticate using the storage account's access keys, or set AZURE_STORAGE_SAS_TOKEN to make use of SAS tokens.

For deployments where Azure Storage is not under AzurePuplicCloud environment, WAL-G need to use different Azure Storage endpoint. You can use optional setting AZURE_STORAGE_SAS_TOKEN to select the correct Azure Storage endpoint. Available setting values: "AzurePublicCloud", "AzureUSGovernmentCloud", "AzureChinaCloud", "AzureGermanCloud". If setting is omitted or has a value different to the ones defined here, WAL-G will default to the Azure Storage endpoint for AzurePublicCloud.

WAL-G sets default upload buffer size to 64 Megabytes and uses 3 buffers by default. However, users can choose to override these values by setting optional environment variables.

  • WALG_AZURE_BUFFER_SIZE (e.g. 33554432)

Overrides the default upload buffer size of 8388608 bytes (8 MB). Note that the size of the buffer must be specified in bytes. Therefore, to use 32 MB sized buffers, this variable should be set to 33554432 bytes.


Overrides the default maximum number of upload buffers. By default, at most 4 buffers are used concurrently.


To store backups in Swift object storage, WAL-G requires that this variable be set:

  • WALG_SWIFT_PREFIX to specify where to store backups in Swift object storage (e.g. swift://test-container/walg-folder)

WAL-G determines Swift object storage credentials using openStack default credentials. You can use any of V1, V2, V3 of the SwiftStack Auth middleware to provide Swift object storage credentials.

File system

To store backups on files system, WAL-G requires that these variables be set:

  • WALG_FILE_PREFIX (e.g. /tmp/wal-g-test-data)

Please, keep in mind that by default storing backups on disk along with database is not safe. Do not use it as a disaster recovery plan.


To store backups via ssh, WAL-G requires that these variables be set: * WALG_SSH_PREFIX (e.g. ssh://localhost/walg-folder) * SSH_PORT ssh connection port * SSH_USERNAME connect with username * SSH_PASSWORD connect with password * SSH_PRIVATE_KEY_PATH or connect with a SSH KEY by specifying its full path


Example: Using Minio.io S3-compatible storage

AWS_ACCESS_KEY_ID: "<minio-key>"
AWS_SECRET_ACCESS_KEY: "<minio-secret>"
WALG_S3_PREFIX: "s3://my-minio-bucket/sub-dir"
AWS_ENDPOINT: "http://minio:9000"
AWS_REGION: us-east-1
WALG_S3_CA_CERT_FILE: "/path/to/custom/ca/file"