The default behavior is to maintain the source and destination nodes synchronized with each other. Therefore, if one or more files are deleted from the source, they will also be removed from the destination. The following configuration affects this default behavior:

1 - Unchecking the Delete Files option in the profile

When the Delete Files option is not checked, the files on the destination will not be removed if they are removed from the source. Since the files are not deleted, a restore operation will also restore files that were deleted by the user at some point.

2 - Specifying a Delete Retention Period

Optionally, you can specify a period in number of days to retain deleted files on the server. This is referred to as the Delete Retention option. This causes the destination (Syncrify Server) to retain files for the specified number of days. For example, selecting a value of 10 days means that when a file is deleted on the client, the same file will be removed permanently from the server after ten days.

Selection filters provide a convenient way to include and exclude files. For example, if your goal is to only backup images in a folder, you can use a selection filter like:

*.png|*.jpg|*.gif|*.bmp

The above selection filter will only back up images with popular file extensions listed above.

Similar to file inclusion rules, you can specify rules to exclude specific files by adding a ^ symbol. For example, the following filter rule will exclude temporary files:

^*.tmp

It is essential to understand the rules for selection filters before using them. Specifying an incorrect selection filter rule can potentially result in the deletion of files on the server.

Important: Specifying a new selection filter may not take effect immediately when the Delete Retention period is specified. This is because files excluded due to filtering rules will remain on the server for the specified retention period.

Types of Selection Filters

Selection filters are defined in three locations:

1. Global Filters - Value for this filter affects every user in Syncrify. Go to Configuration, select Advanced Configuration, under More Configuration Options, and then specify a value for the Global Selection Filter field.
2. User Filter - This affect every profile for a single user and is specified on Syncrify Server. Go to Manager Users, click the modify icon under the Action column and specify a value for the Selection Filter field.
3. Top-Level Folder - Every top-level folder can have a selection filter. Unlike the other two filters, this value is specified using Syncrify Client. To view or modify this value, right-click on any top-level folder in Syncrify Client and click Selection Filter.

Users can exclude specific folders from synchronization. Excluding a folder will also exclude all files and folders located under the same tree. Similar to selection filters, excluded files will remain on the server for the specified number of days for Delete Retention.

Toggling the encryption option or changing the password causes the entire dataset to be backed up again. This means every file will be deleted from the server and will be sent again from the client using the new encryption value. The Delete Retention period is ignored in this scenario.

Syncrify computes the MD5 signatures of a file before and after a backup to ensure they remain synchronized. On rare occasions, a file transfer may result in corrupted data, causing the MD5 hash to not match between the two ends. In such cases, Syncrify Server will remove the copy of the files with non-matching hashes. The next backup will transfer the file again.