S3 File Gatewayを介して作成されたオブジェクトにどのようなメタデータが付与されているのか確認してみた

$ sudo mount -t nfs -o nolock,hard 172.31.33.190:/sgw-2025-08-31-w5b1b /mnt/sgw

$ df -hT -t nfs4
Filesystem                          Type  Size  Used Avail Use% Mounted on
172.31.33.190:/sgw-2025-08-31-w5b1b nfs4  8.0E     0  8.0E   0% /mnt/sgw

$ sudo mkdir -p /mnt/sgw/test
$ echo test > /mnt/sgw/test.txt

$ ls -ld /mnt/sgw/test
drwxr-xr-x. 1 nobody nobody 0 Aug 31 14:00 /mnt/sgw/test

$ ls -l /mnt/sgw/test
total 0

$ echo test | sudo tee /mnt/sgw/test/test.txt > /dev/null
$ ls -l /mnt/sgw/test
total 1
-rw-r--r--. 1 nobody nobody 5 Aug 31 14:02 test.txt

$ ls -ln /mnt/sgw/test
total 1
-rw-r--r--. 1 65534 65534 5 Aug 31 14:02 test.txt

>  aws s3api head-object --bucket sgw-2025-08-31-w5b1b --key test/
{
    "AcceptRanges": "bytes",
    "LastModified": "2025-08-31T14:28:52+00:00",
    "ContentLength": 0,
    "ETag": "\"d41d8cd98f00b204e9800998ecf8427e\"",
    "ContentType": "application/octet-stream",
    "ServerSideEncryption": "AES256",
    "Metadata": {
        "user-agent": "aws-storage-gateway",
        "user-agent-id": "sgw-D5E2A9BC",
        "aws-sgw": "a0ca9a363dec9e2d98d7990abd2bfaefcd38e26fb5130b7c406864ad05519cad",
        "file-ctime": "1756650495599000000ns",
        "file-owner": "65534",
        "file-permissions": "0755",
        "file-group": "65534",
        "file-mtime": "1756648841831800556ns"
    }
}

$ sudo chown root:root /mnt/sgw/test/test.txt
$ sudo chmod 400 /mnt/sgw/test/test.txt
$ sudo ls -ln /mnt/sgw/test
total 1
-r--------. 1 65534 65534 5 Aug 31 14:02 test.txt

> net use Z: \\172.31.33.190\sgw-2025-08-31-nmk3t
Enter the user name for '172.31.33.190': Enter the password for 172.31.33.190:
The command completed successfully.

> Get-PSDrive Z

Name           Used (GB)     Free (GB) Provider      Root                                               CurrentLocation
----           ---------     --------- --------      ----                                               ---------------
Z                   0.00 8589934592.00 FileSystem    \\172.31.33.190\sgw-2025-08-31-n...

> mkdir z:\test

    Directory: Z:\

Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----         8/31/2025   2:07 PM                test

> echo test > Z:\test\test.txt
> ls Z:\test

    Directory: Z:\test

Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----         8/31/2025   2:07 PM             14 test.txt

>  aws s3api head-object --bucket sgw-2025-08-31-nmk3t --key test/
{
    "AcceptRanges": "bytes",
    "LastModified": "2025-08-31T14:07:52+00:00",
    "ContentLength": 0,
    "ETag": "\"d41d8cd98f00b204e9800998ecf8427e\"",
    "ContentType": "application/octet-stream",
    "ServerSideEncryption": "AES256",
    "Metadata": {
        "user-agent": "aws-storage-gateway",
        "user-agent-id": "sgw-D5E2A9BC",
        "aws-sgw": "342916150b03d765cda733e8ed05c3b78668af34ec09f75f3095764b04e9173d",
        "file-acl": "EQUFFZmtvIwP/+b7vg//8MPcCfQDBQUVma28jA//5vu+D//ww9wJgQSEBAEAE/n/AQEA",
        "file-ctime": "1756649241689000000ns",
        "file-dosattr": "16",
        "file-owner": "67166",
        "file-permissions": "0777",
        "file-group": "67179",
        "file-mtime": "1756649241689000000ns"
    }
}