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I'd like to graph the size (in bytes, and # of items) of an Amazon S3 bucket and am looking for an efficient way to get the data.

The s3cmd tools provide a way to get the total file size using s3cmd du s3://bucket_name, but I'm worried about its ability to scale since it looks like it fetches data about every file and calculates its own sum. Since Amazon charges users in GB-Months it seems odd that they don't expose this value directly.

Although Amazon's REST API returns the number of items in a bucket, [s3cmd] doesn't seem to expose it. I could do s3cmd ls -r s3://bucket_name | wc -l but that seems like a hack.

The Ruby AWS::S3 library looked promising, but only provides the # of bucket items, not the total bucket size.

Is anyone aware of any other command line tools or libraries (prefer Perl, PHP, Python, or Ruby) which provide ways of getting this data?

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11 Answers 11

up vote 11 down vote accepted

The AWS CLI now supports the --query parameter which takes a JMESPath expressions.

This means you can sum the size values given by list-objects using sum(Contents[].Size) and count like length(Contents[]).

This can be be run using the official AWS CLI as below and was introduced in Feb 2014

 aws s3api list-objects --bucket BUCKETNAME --output json --query "[sum(Contents[].Size), length(Contents[])]"
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Since it's the first result for google, I reply later. s3cmd can do this : s3cmd du s3://bucket-name

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Thanks. Here's some timing. On a bucket that holds an s3ql deduplicated filesystem with about a million files using about 33 GB of undupicated data, and about 93000 s3 objects, s3cmd du took about 4 minutes to compute the answer. I'm curious to know how that compares with other approaches like the php one described elsewhere here. –  nealmcb Jul 10 '12 at 23:46
It is slow because the S3 ListObjects API call returns objects in pages of 1000 objects. As I/O is by far the limiting factor I think any solution will be relatively slow over 93000 objects. –  David Caunt Apr 20 '13 at 13:54
s4cmd can also do the same thing, with the added benefit of multi-threading the requests to S3's API to compute the result faster. The tool hasn't been updated recently, but the Internet passer-by may find it useful. –  Nick Chammas Jul 7 '14 at 17:34

If you download a usage report, you can graph the daily values for the TimedStorage-ByteHrs field.

If you want that number in GiB, just divide by 1024 * 1024 * 1024 * 24 (that's GiB-hours for a 24-hour cycle). If you want the number in bytes, just divide by 24 and graph away.

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I used the S3 REST/Curl API listed earlier in this thread and did this:

if (!class_exists('S3')) require_once 'S3.php';

// Instantiate the class
$s3 = new S3('accessKeyId', 'secretAccessKey');
S3::$useSSL = false;

// List your buckets:
echo "S3::listBuckets(): ";
echo '<pre>' . print_r($s3->listBuckets(), 1). '</pre>';

$totalSize = 0;
$objects = $s3->getBucket('name-of-your-bucket');
foreach ($objects as $name => $val) {
    // If you want to get the size of a particular directory, you can do
    // only that.
    // if (strpos($name, 'directory/sub-directory') !== false)
    $totalSize += $val['size'];

echo ($totalSize / 1024 / 1024 / 1024) . ' GB';
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... A bit late but, the best way I found is by using the reports in the AWS portal. I made a PHP class for downloading and parsing the reports. With it you can get total number of objects for each bucket, total size in GB or byte hrs and more.

Check it out and let me know if was helpful


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This is an interesting solution, although a little hackish. Worried about it breaking if/when Amazon changes their site, but I may have to try this out once I have enough objects that the other way becomes too slow. Another benefit of this approach is that you don't get charged for any API calls. –  Garret Heaton Dec 21 '09 at 16:16
. . . its an assumption but, if Amazon do change the look of their site, I doubt they would change the back end much, meaning the current GET and POST queries should work. I will maintain the class in the event it does break anyway as I use it often. –  Corey Sewell Dec 22 '09 at 0:26

So trolling around through the API and playing some same queries, S3 will produce the entire contents of a bucket in one request and it doesn't need to descend into directories. The results then just requiring summing through the various XML elements, and not repeated calls. I don't have a sample bucket that has thousands of items so I don't know how well it will scale, but it seems reasonably simple.

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This does seem to be the best option. Will update this post in the future if it scales poorly and I need to do something else. The library that ended up providing easy access to the raw API results was this PHP one: undesigned.org.za/2007/10/22/amazon-s3-php-class –  Garret Heaton Nov 16 '09 at 15:20

I wrote a Bash script, s3-du.sh that will list files in bucket with s3ls, and print count of files, and sizes like

s3-du.sh testbucket.jonzobrist.com
149 files in bucket testbucket.jonzobrist.com
11760850920 B
11485205 KB
11216 MB
10 GB

More info and full script here :


It does do subdirectory size, as Amazon returns the directory name and the size of all of it's contents.

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Hey there is a metdata search tool for AWS S3 at https://s3search.p3-labs.com/.This tool gives statstics about objects in a bucket with search on metadata.

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Also Hanzo S3 Tools does this. Once installed, you can do:

s3ls -s -H bucketname

But I believe this is also summed on the client side and not retrieved through the AWS API.

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By Cloudberry program is also possible to list the size of the bucket, amount of folders and total files, clicking "properties" right on top of the bucket.

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You can use the s3cmd utility, e.g.:

s3cmd du -H s3://Mybucket
97G      s3://Mybucket/
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