Amazon Cloud Recharge: AWS Storage Gateway File Gateway Synchronizes Local Files to S3 Failure Troubleshooting Guide

cloud 2026-08-04 阅读 2

In a hybrid cloud architecture, the AWS S3 File Gateway (file gateway) is a bridge between an enterprise's local data center and AWS cloud storage. It allows on-premises applications to write files to the gateway via standard NFS or SMB protocols, and the gateway automatically synchronizes these files asynchronously to an Amazon S3 bucket.

However, in actual operation and maintenance, many engineers will encounter"

The local file was written in, but it was not seen in S3 for a long time.

"Or"

Gateway prompt error, synchronization directly interrupted

"The embarrassing situation. This kind of question seems simple, but it may involve

Account bills, permission policies, network time, local cache disks, and S3 rules

And so on many levels of reason.

This article combines the actual combat experience of front-line operation and maintenance to sort out a set of troubleshooting ideas from shallow to deep to help you quickly locate and solve the problem of Storage Gateway synchronization failure.

1. first step: check the basic service and account status (premise that cannot be ignored)

Before in-depth troubleshooting of various complex network and permission configurations, first confirm the health status of the AWS account itself and the underlying services.

1. Check AWS account status and billing

Many teams tend to overlook the most basic when troubleshooting technical details.

Account Status

. If AWS account resources are suspended or restricted (for example, API call permission is restricted) due to arrears, the background service of Storage Gateway will not be able to write data to S3.

Check item: Log in to the AWS console to check whether there are overdue bills or account freeze prompts on the Billing interface.

Operation and maintenance suggestion: When deploying the production environment, enterprises must ensure that the AWS account recharge channel is smooth and configure the CloudWatch bill alarm (Billing Alerts). At the same time, it is recommended to bind available credit cards or complete AWS account recharge and quota warning through compliant AWS agents to avoid interruption of the enterprise's local data pipeline to the cloud due to sudden arrears.

2. Check the Gateway running status and CloudWatch health log

Verify that CloudWatch Health Logs is enabled. Many synchronization exceptions (such as S3AccessDenied and GatewayClockOutOfSync) of the file gateway are directly output in the CloudWatch log group, which is the most direct basis for diagnosing problems.

2. Step 2: Identity Authentication and IAM Permission Troubleshooting

Data cannot be written to S3 from the gateway, one of the most common reasons

Insufficient permissions

. The gateway needs to use an IAM Role (role)

3 buckets for read and write operations.

[Local NFS/SMB Client]

Write

▼

[AWS Storage Gateway Virtual Machine]

│ Authentication and signing using IAM Role

▼

[Amazon S3 Bucket]

1. Check the permissions policy of the IAM Role (Policy)

Check that the gateway-bound IAM Role has the following base permissions on the target S3 bucket:

s3:GetBucketLocation (get bucket area)

s3:ListBucket (list bucket contents)

s3:GetObject (read object)

s3:PutObject (upload file object)

S3: PutObjectAcl (if ACL related settings are enabled)

2. Check the S3 Bucket Policy

Confirm whether there is an explicit denial in the bucket policy (

Deny

) statement. For example:

Is it restricted to allow only specific IP or VPC access, while blocking the egress IP of the file gateway?

Is the policy to force HTTPs transfers enabled, but the gateway configuration fails to match?

3. KMS encryption key permissions (if SSE-KMS is enabled)

If the target S3 bucket has custom KMS key encryption (SSE-KMS) turned on, the IAM Role must have S3 permissions in

KMS Key Policy

is granted the following permissions:

kms:GenerateDataKey

kms:Decrypt

The lack of KMS permissions causes the gateway to call

PutObject

When thrown directly

Access Denied

Error.

4. VPC Endpoint policy restrictions

If the gateway communicates with S3 through a VPC endpoint (VPC Endpoint), check whether the Endpoint policy allows the IAM role to access the destination S3 bucket.

3. step 3: network and system time synchronization check

Storage Gateway are extremely demanding on the accuracy of network connectivity and local system time.

1. System time deviation (GatewayClockOutOfSync)

AWS API relies on the request signature mechanism, and the signature is time-sensitive. If the system time of the virtual machine (VMware, Hyper-V, or EC2) where the Storage Gateway is located is the same as the AWS server time

Deviation over

5 minutes

AWS rejects all requests for the gateway and outputs

GatewayClockOutOfSync

Error.

Troubleshooting method: Log in to the gateway local console (Local Console) and check the NTP configuration.

Solution: Ensure that the gateway VM can connect to the NTP server (for example, 0.amazon.pool.ntp.org or the internal NTP service), or enable the time synchronization function of the host.

2. Outbound network port patency

The gateway requires an outbound connection to the AWS service. Verify that your firewall or security group does not block the following ports:

443 (HTTPS): The gateway's core communication port with AWS Storage Gateway and S3 endpoints.

80 (HTTP): Required for gateway activation (activation phase only).

22 (SSH/Support Channel): Open the AWS official technical support channel if necessary.

4. Step 4: Local Cache and Hardware Resource Bottleneck

The file gateway adopts the architecture of "local cache + background asynchronous upload. When the local write volume is too large or the hardware resources are insufficient, the file will be stuck in the local cache and cannot be synchronized to the cloud in time.

1. The proportion of cached dirty data is too high (CachePercentDirty monitoring items)

Open the CloudWatch Metrics and find

CachePercentDirty

(Dirty Data Percentage) Indicator.

Normal state: After writing data, it rises, and after uploading, it falls back to close to 0%.

Abnormal status: If the CachePercentDirty is higher than 80% for a long time, the writing speed of the local client is much faster than the uploading speed of the gateway to S3.

Response Strategies

Check whether the exit broadband is full and increase the network bandwidth if necessary.

Add more local Cache disks for the gateway.

Control the write rate on the client to avoid bursting large files and bursting the cache.

2. Local disk I/O bottleneck (IoWaitPercent)

Observe the CloudWatch

IoWaitPercent

Indicator. If the value continuously exceeds

10%

, indicating that there is a bottleneck in the read and write performance of the local cache disk (for example, using a low-speed HDD instead of SSD/NVMe).

Solution: It is recommended to replace the cache disk with an NVMe or SSD solid state disk with high IOPS, or split a large cache disk into multiple independent physical disks and mount them to virtual machines to distribute I/O pressure.

The Windows permission (ACL) entry is too long (Error 1344)

If the file is shared through the SMB protocol, when trying to synchronize the file contains too complex Win

Dows permissions may be triggered when setting the file

Error: 1344 (0x00000540)

Cause: The AWS S3 File Gateway only supports storing up to 10 access control entries (ACEs) per file or directory.

Workaround: Clean and streamline the list of Windows access permissions for the file or folder, merge the user groups, and ensure that the number of ACEs is less than 10.

5. Step 5: S3 side changes are not reflected locally (reverse synchronization cognitive misunderstanding)

There is a special case that is often mistaken for a "synchronization failure":

The user directly uploads the file in the S3 console, but it is not visible in the local NFS/SMB mount point.

Principle: To maintain high performance, the file gateway caches S3 metadata. By default, it does not poll S3 buckets for internal changes in real time.

Workaround: Manually refresh: Select the file share in the console, click Refresh Cache, or execute the aws storagegateway refresh-cache command through the AWS CLI. Automatic refresh: Configure the automatic cache refresh policy interval in the file share settings.

Summary of 6. CheckList

When AWS Storage Gateway file synchronization fails, you can quickly check the table by referring to the following table:

Troubleshooting Level

Inspection Items

Common Phenomena/Error Codes