Configuring for Small File Uploads

If you need to upload many small files (100 Kb or less) to object storage, Aspera recommends using the configuration described below to optimize transfer speed. These instructions require you to configure settings on the server and the client, both of which must be running an Aspera product version 3.4.6 or higher. Check the version of your Aspera product by running the following command:

# ascp -A

Configuring the Server

Disable pre-calculating job size.
You can disable the pre-calculate job size option by editing aspera.conf or through Aspera Console.
- Editing aspera.conf: Run the following command as root:
```
# asconfigurator -x "set_node_data;pre_calculate_job_size,no"
```
  This command adds the following text to the <file_system> section of /opt/aspera/etc/aspera.conf:
```
<file_system>
    ...
    <pre_calculate_job_size>no</pre_calculate_job_size>
</file_system>
```
- Using Aspera Console: Log into Console as admin and go to Nodes > edit > Configuration > Advanced File Handling. In the row for Pre-Calculate Job Size, select the OVERRIDE box, then select no from the drop-down menu.

Run the Trapd setup script:

# /opt/aspera/bin/astrap-config.sh enable

Modify the Trapd configuration.
Open /opt/aspera/etc/trapd/trap.properties. Locate the following line:
```
#aspera.session.upload.start-check-small-file.enabled=true
```
Uncomment the line and change the value to false:
```
aspera.session.upload.start-check-small-file.enabled=false
```
Note: After making this change, Trap does not check if a directory already exists in your object storage with the same name as a file you are transferring into the storage. For example, if you upload a file named "foo" and your object storage container already has a directory named "foo," your container will have both a file "foo" and a directory "foo."
Restart Trapd:
```
# /etc/init.d/asperatrapd restart
```

Configuring the Client

Transfers initiated by the client can be optimized for many small files to object storage from the Aspera GUI or by using ascp command options.

Disable resuming incomplete files. (Recommended)
In the GUI, click Connections. Select the connection you wish to modify then click File Handling. Unselect Resume incomplete files. Click OK to apply this setting to all transfers with this connection.

Transfers initiated from the command line automatically re-transfer the entire file by default (equivalent to -k 0), unless preceding transfers have specified a different value for -k. In this case, you must use the -k 0 option.
Configure the resume options if resume must be used.
If you must have resume enabled, the following settings optimize resume for transfer speed.
In the GUI, click Connections. Select the connection you wish to modify then click File Handling. Under When checking files for differences, select Compare file attributes from the drop-down menu. Under When a complete file already exists at the destination, select Always overwrite from the drop-down menu. Click OK to apply these settings to all transfers with this connection.

To specify the same settings in an ascp command line transfer, run ascp with the following option:
```
$> ascp -k 1 --overwrite=always ...
```
Disable calculation of source files size before transferring with the GUI.
This optional step makes the start of the transfer faster by avoiding the calculation before the transfer commences. Transfers initiated from the command line do not calculate source files size before transferring by default.
In the GUI, click Connections. Select the connection you wish to modify then click Transfer. Select Disable calculation of source files size before transferring. Click OK to apply this setting to all transfers with this connection. If you do not see this option, click Show Advanced Settings to make it visible.