Optimize Uploaded File for Comparison by Content (MD5)
The Optimize Uploaded File for Comparison by Content (MD5) option performs in-cloud copying for comparison purposes.
Most storage providers (for example, Amazon S3, Wasabi, and many others) use so-called multiparts to upload large objects.
The ETag for an object created using the multipart upload API is calculated with an algorithm different from the MD5 sum for each file chunk, so it is impossible to use them for comparison. An in-cloud copying operation can solve this problem if a storage provider supports such operations. After in-cloud copying, an ETag has the correct values for the whole file. Further, this sum can be used to compare files by content.
Note that when the Optimize Uploaded File for Comparison by Content (MD5) option is enabled, it performs additional PUT requests for every file copied in the cloud.
A new file version is created in the cloud if versioning is enabled on a storage account's bucket.
Enable or Disable This Option
To manage the Optimize Uploaded File for Comparison by Content (MD5) option, proceed as follows:
- Select Options.
- Switch to the Multipart Upload tab.
- Select or clear the Optimize Uploaded File for Comparison by Content (MD5) check box.
- Click OK.