Synopsis

gsutil cp [OPTION]... src_url dst_url gsutil cp [OPTION]... src_url... dst_url gsutil cp [OPTION]... -I dst_url

Description

The gsutil cp command allows you to copy data between your local file system and the cloud, copy data within the cloud, and copy data between cloud storage providers. For example, to copy all text files from the local directory to a bucket you could do:

gsutil cp *.txt gs://my_bucket

Similarly, you can download text files from a bucket by doing:

gsutil cp gs://my_bucket/*.txt .

If you want to copy an entire directory tree you need to use the -R option:

gsutil cp -R dir gs://my_bucket

If you have a large number of files to upload you might want to use the gsutil -m option, to perform a parallel (multi-threaded/multi-processing) copy:

gsutil -m cp -R dir gs://my_bucket

You can pass a list of URLs (one per line) to copy on STDIN instead of as command line arguments by using the -I option. This allows you to use gsutil in a pipeline to upload or download files / objects as generated by a program, such as:

some_program | gsutil -m cp -I gs://my_bucket

or:

some_program | gsutil -m cp -I ./download_dir

The contents of STDIN can name files, cloud URLs, and wildcards of files and cloud URLs.

How Names Are Constructed

The gsutil cp command strives to name objects in a way consistent with how Linux cp works, which causes names to be constructed in varying ways depending on whether you’re performing a recursive directory copy or copying individually named objects; and whether you’re copying to an existing or non-existent directory.

When performing recursive directory copies, object names are constructed that mirror the source directory structure starting at the point of recursive processing. For example, the command:

gsutil cp -R dir1/dir2 gs://my_bucket

will create objects named like gs://my_bucket/dir2/a/b/c, assuming dir1/dir2 contains the file a/b/c.

In contrast, copying individually named files will result in objects named by the final path component of the source files. For example, the command:

gsutil cp dir1/dir2/** gs://my_bucket

will create objects named like gs://my_bucket/c.

The same rules apply for downloads: recursive copies of buckets and bucket subdirectories produce a mirrored filename structure, while copying individually (or wildcard) named objects produce flatly named files.

Note that in the above example the ‘**’ wildcard matches all names anywhere under dir. The wildcard ‘*’ will match names just one level deep. For more details see gsutil help wildcards .

There’s an additional wrinkle when working with subdirectories: the resulting names depend on whether the destination subdirectory exists. For example, if gs://my_bucket/subdir exists as a subdirectory, the command:

gsutil cp -R dir1/dir2 gs://my_bucket/subdir

will create objects named like gs://my_bucket/subdir/dir2/a/b/c. In contrast, if gs://my_bucket/subdir does not exist, this same gsutil cp command will create objects named like gs://my_bucket/subdir/a/b/c.

Note: If you use the Google Developers Console to create folders, it does so by creating a “placeholder” object that ends with a “/” character. gsutil skips these objects when downloading from the cloud to the local file system, because attempting to create a file that ends with a “/” is not allowed on Linux and MacOS. Because of this, it is recommended that you not create objects that end with “/” (unless you don’t need to be able to download such objects using gsutil).

Copying To/from Subdirectories; Distributing Transfers Across Machines

You can use gsutil to copy to and from subdirectories by using a command like:

gsutil cp -R dir gs://my_bucket/data

This will cause dir and all of its files and nested subdirectories to be copied under the specified destination, resulting in objects with names like gs://my_bucket/data/dir/a/b/c. Similarly you can download from bucket subdirectories by using a command like:

gsutil cp -R gs://my_bucket/data dir

This will cause everything nested under gs://my_bucket/data to be downloaded into dir, resulting in files with names like dir/data/a/b/c.

Copying subdirectories is useful if you want to add data to an existing bucket directory structure over time. It’s also useful if you want to parallelize uploads and downloads across multiple machines (often reducing overall transfer time compared with simply running gsutil -m cp on one machine). For example, if your bucket contains this structure:

gs://my_bucket/data/result_set_01/
gs://my_bucket/data/result_set_02/
...
gs://my_bucket/data/result_set_99/

you could perform concurrent downloads across 3 machines by running these commands on each machine, respectively:

gsutil -m cp -R gs://my_bucket/data/result_set_[0-3]* dir
gsutil -m cp -R gs://my_bucket/data/result_set_[4-6]* dir
gsutil -m cp -R gs://my_bucket/data/result_set_[7-9]* dir

Note that dir could be a local directory on each machine, or it could be a directory mounted off of a shared file server; whether the latter performs acceptably may depend on a number of things, so we recommend you experiment and find out what works best for you.

Copying In The Cloud And Metadata Preservation

If both the source and destination URL are cloud URLs from the same provider, gsutil copies data “in the cloud” (i.e., without downloading to and uploading from the machine where you run gsutil). In addition to the performance and cost advantages of doing this, copying in the cloud preserves metadata (like Content-Type and Cache-Control). In contrast, when you download data from the cloud it ends up in a file, which has no associated metadata. Thus, unless you have some way to hold on to or re-create that metadata, downloading to a file will not retain the metadata.

Note that by default, the gsutil cp command does not copy the object ACL to the new object, and instead will use the default bucket ACL (see gsutil help defacl ). You can override this behavior with the -p option (see OPTIONS below).

One additional note about copying in the cloud: If the destination bucket has versioning enabled, gsutil cp will copy all versions of the source object(s). For example:

gsutil cp gs://bucket1/obj gs://bucket2

will cause all versions of gs://bucket1/obj to be copied to gs://bucket2.

Checksum Validation And Failure Handling

At the end of every upload or download, the gsutil cp command validates that that the checksum of the source file/object matches the checksum of the destination file/object. If the checksums do not match, gsutil will delete the invalid copy and print a warning message. This very rarely happens, but if it does, please contact gs-team @ google . com .

The cp command will retry when failures occur, but if enough failures happen during a particular copy or delete operation the command will skip that object and move on. At the end of the copy run if any failures were not successfully retried, the cp command will report the count of failures, and exit with non-zero status.

Note that there are cases where retrying will never succeed, such as if you don’t have write permission to the destination bucket or if the destination path for some objects is longer than the maximum allowed length.

For more details about gsutil’s retry handling, please see gsutil help retries .

Resumable Transfers

gsutil automatically uses the Google Cloud Storage resumable upload feature whenever you use the cp command to upload an object that is larger than 2 MB. You do not need to specify any special command line options to make this happen. If your upload is interrupted you can restart the upload by running the same cp command that you ran to start the upload. Until the upload has completed successfully, it will not be visible at the destination object and will not replace any existing object the upload is intended to overwrite. (However, see the section on PARALLEL COMPOSITE UPLOADS, which may leave temporary component objects in place during the upload process.)

Similarly, gsutil automatically performs resumable downloads (using HTTP standard Range GET operations) whenever you use the cp command to download an object larger than 2 MB. In this case the partially downloaded file will be visible as soon as it starts being written. Thus, before you attempt to use any files downloaded by gsutil you should make sure the download completed successfully, by checking the exit status from the gsutil command. This can be done in a bash script, for example, by doing:

gsutil cp gs://your-bucket/your-object ./local-file
if [ "$status" -ne "0" ] ; then
  << Code that handles failures >>
fi

Resumable uploads and downloads store some state information in a file in ~/.gsutil named by the destination object or file. If you attempt to resume a transfer from a machine with a different directory, the transfer will start over from scratch.

See also gsutil help prod for details on using resumable transfers in production.

Streaming Transfers

Use ‘-‘ in place of src_url or dst_url to perform a streaming transfer. For example:

long_running_computation | gsutil cp - gs://my_bucket/obj

Streaming transfers do not support resumable uploads/downloads. (The Google resumable transfer protocol has a way to support streaming transfers, but gsutil doesn’t currently implement support for this.)

Parallel Composite Uploads

gsutil can automatically use object composition to perform uploads in parallel for large, local files being uploaded to Google Cloud Storage. This means that, if enabled (see next paragraph), a large file will be split into component pieces that will be uploaded in parallel. Those components will then be composed in the cloud, and the temporary components in the cloud will be deleted after successful composition. No additional local disk space is required for this operation.

If the “parallel_composite_upload_threshold” config value is not 0 (which disbles the feature), any file whose size exceeds the specified size will trigger a parallel composite upload. Note that at present parallel composite uploads are disabled by default, because using composite objects requires a compiled crcmod (see gsutil help crcmod ), and for operating systems that don’t already have this package installed this makes gsutil harder to use. Google is actively working with a number of the Linux distributions to get crcmod included with the stock distribution. Once that is done we will re-enable parallel composite uploads by default in gsutil.

The ideal size of a component can also be set with the “parallel_composite_upload_component_size” config variable. See the comments in the .boto config file for details about how these values are used.

If the transfer fails prior to composition, running the command again will take advantage of resumable uploads for those components that failed, and the component objects will be deleted after the first successful attempt. Any temporary objects that were uploaded successfully before gsutil failed will still exist until the upload is completed successfully. The temporary objects will be named in the following fashion: <random ID>/gsutil/tmp/parallel_composite_uploads/for_details_see/gsutil_help_cp/<hash> where <random ID> is some numerical value, and <hash> is an MD5 hash (not related to the hash of the contents of the file or object).

To avoid leaving temporary objects around, you should make sure to check the exit status from the gsutil command. This can be done in a bash script, for example, by doing:

gsutil cp ./local-file gs://your-bucket/your-object
if [ "$status" -ne "0" ] ; then
  << Code that handles failures >>
fi

Or, for copying a directory, use this instead:

gsutil cp -c -L cp.log -R ./dir gs://bucket
if [ "$status" -ne "0" ] ; then
  << Code that handles failures >>
fi

One important caveat is that files uploaded in this fashion are still subject to the maximum number of components limit. For example, if you upload a large file that gets split into 10 components, and try to compose it with another object with 1015 components, the operation will fail because it exceeds the 1024 component limit. If you wish to compose an object later and the component limit is a concern, it is recommended that you disable parallel composite uploads for that transfer.

Also note that an object uploaded using this feature will have a CRC32C hash, but it will not have an MD5 hash. For details see gsutil help crc32c .

Note that this feature can be completely disabled by setting the “parallel_composite_upload_threshold” variable in the .boto config file to 0.

Changing Temp Directories

gsutil writes data to a temporary directory in several cases:

• when compressing data to be uploaded (see the -z option)
• when decompressing data being downloaded (when the data has Content-Encoding:gzip, e.g., as happens when uploaded using gsutil cp -z)
• when running integration tests (using the gsutil test command)

In these cases it’s possible the temp file location on your system that gsutil selects by default may not have enough space. If you find that gsutil runs out of space during one of these operations (e.g., raising “CommandException: Inadequate temp space available to compress <your file>” during a gsutil cp -z operation), you can change where it writes these temp files by setting the TMPDIR environment variable. On Linux and MacOS you can do this either by running gsutil this way:

TMPDIR=/some/directory gsutil cp ...

or by adding this line to your ~/.bashrc file and then restarting the shell before running gsutil:

export TMPDIR=/some/directory

On Windows 7 you can change the TMPDIR environment variable from Start -> Computer -> System -> Advanced System Settings -> Environment Variables. You need to reboot after making this change for it to take effect. (Rebooting is not necessary after running the export command on Linux and MacOS.)

Options

gsutil cp -D -p gs://bucket/obj gs://bucket/obj_tmp
gsutil mv -p gs://bucket/obj_tmp gs://bucket/obj

until gsutil cp -c -L cp.log -R ./dir gs://bucket; do
  sleep 1
done

gsutil cp -z html -a public-read cattypes.html gs://mycats