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Torch Object Storage

FAQ

Object FAQ

Category	FAQ
Uploading objects	Why does uploading objects to the console feel slow? What restrictions does TOS impose on the types and sizes of objects that can be uploaded? Does TOS support resumable uploads? Does TOS support batch uploads? Why do I receive a 400 error when uploading objects with the multipart upload method? How can I improve the upload speed when uploading many small objects?
Downloading objects	Does TOS support batch downloads?
Managing objects	Can an object be recovered after it has been deleted or overwritten in TOS? How can I restore an object that was accidentally deleted in TOS? What is the difference between a prefix and a folder? Does TOS support batch deletions? How can I change how long an object is shared via URL? How do I set the validity period for publicly readable objects? How can I list the objects in a specific directory?

Uploading objects

Why does uploading objects to the console feel slow?

TOS does not limit your upload or download speeds. If uploading objects via the console feels slow, possible reasons include the following:

For single uploads, if your object is large (in the megabyte range), the console will upload it through your browser over the public network. The upload speed is limited by your local bandwidth from the internet to the TOS servers. Upload times may be longer than expected if your connection is weak or slow. For example, uploads from a mobile browser may take longer.

During batch uploads, the console is subject to the built-in concurrency limits of the browser. For example, Google Chrome limits concurrency to six, which can prevent highly concurrent upload requests and result in slower overall batch upload speeds.

To improve upload speed, we recommend using TOS tools such as tosutil and TOS Browser.

What restrictions does TOS impose on the types and sizes of objects that can be uploaded?

TOS supports direct uploads of up to 5 GiB and multipart uploads of up to 48.8 TiB.

There are no restrictions on object type. If you require additional restrictions, you must implement them on your end.

Does TOS support resumable uploads?

The following table shows which TOS management tools support resumable uploads.

TOS management tool	Resumable uploads
TOS console	Not supported
tosutil	Supported
TOS Browser	Supported
APIs	Not supported
SDKs	Java: Supported Python: Supported Go: Supported C++: Supported Node.js: Supported Browser.js: Supported PHP: Not supported iOS: Not supported Android: Supported

Does TOS support batch uploads?

The following table shows which TOS management tools support batch uploads.

TOS management tool	Batch uploads
TOS console	Supported
tosutil	Supported
TOS Browser	Supported
APIs	Not supported
SDKs	Not supported

Why do I receive a 400 error when uploading objects with the multipart upload method?

One possible cause is that the part size does not meet the minimum requirement. When using multipart upload, all parts except the last one must be at least 4 MB. We recommend adjusting the part size.

How can I improve the upload speed when uploading many small objects?

tosutil supports adjusting concurrency via the -j and -p parameters. We recommend using tosutil for this scenario. For more information, see Recommendations for optimizing performance.

Downloading objects

Does TOS support batch downloads?

The following table shows which TOS management tools support batch downloads.

TOS management tool	Batch downloads
TOS console	Not supported
tosutil	Supported
TOS Browser	Supported
APIs	Not supported
SDKs	Not supported

Managing objects

Can an object be recovered after it has been deleted or overwritten in TOS?

Yes, if versioning is enabled.

If versioning is not enabled, the object cannot be recovered. Proceed with caution.

How can I restore an object that was accidentally deleted in TOS?

Once an object is deleted or overwritten, it cannot be recovered. Proceed with caution. To avoid accidental deletion, we recommend enabling versioning. With versioning enabled, TOS automatically retains historical versions of the original data when you delete or overwrite it. If you make a mistake, you can restore the data to an earlier version, which prevents data loss or modification. For more information, see Versioning.

What is the difference between a prefix and a folder?

Object storage uses a flat structure and does not have folders. However, you can simulate folders using prefixes, such as a/b. In object storage, a folder is a special type of prefix that ends with a slash (/).

Does TOS support batch deletions?

The following table shows which TOS management tools support batch deletions.

tip

The console is subject to the browser's concurrency and memory constraints during batch deletion of objects, which may slow down the process. For this reason, we recommend using either TOS Browser or tosutil.

TOS management tool	Batch deletions
TOS console	Supported
tosutil	Supported
TOS Browser	Supported
APIs	Not supported
SDKs	Not supported

How can I change how long an object is shared via URL?

The expiration time of a file-sharing URL cannot be changed after the URL is created. To use a different expiration time, generate a new URL. The range of supported expiration times varies by sharing method. For more information, see Sharing objects.

How do I set the validity period for publicly readable objects?

Publicly readable objects are valid indefinitely. If you no longer want them to be publicly readable, you can change their predefined access control lists (ACLs) to "private". For more information, see Granting public read access to multiple objects simultaneously.

How can I list the objects in a specific directory?

You can use the bucket inventory feature for this purpose. For more information, see Bucket inventory. Alternatively, you can use the ls command in tosutil. For more information, see Listing objects or object versions.

Last updated: 2026.10.22 14:12:38