Data access

4. Data access#

In May 2024, data security policies were implemented at BMM. This has impact on user operations and data access.

Data is now written to a secure location on central storage. Access to your data now requires authentication using your BNL domain account, your password, and two-factor authentication with DUO or a Yubi key.

The beamline operator account does not have access to user’s data.

This section of the beamline manual explains how to access your data during and after your experiment.

4.1. Downloading data#

4.1.1. SFTP Client#

You will need an sftp client.

  • Cross-platform: FileZilla. This is a free program available for Windows, Apple, and Linux. The explanation below will be made using FileZilla.

  • Windows users: A popular option is WinSCP. Be careful at the WinSCP website. You will see multiple pop-up adds with download links to other software packages. Be careful to click on the link to the WinSCP package.

  • Mac users: Other options are Termius and Flow.

  • Linux users: Your desktop file manager likely has an sftp client built in. Try typing sftp://<username>@sftp.nsls2.bnl.gov into your file manager or creat a new network drive using ssh and sftp.nsls2.bnl.gov.

    sshfs is an excellent solution. sshfs allows you to easily mount the remote sftp site to a local mount point, allowing you to browse the remote site as if it were a local folder. For example, I do the following to mount the data folder locally on my laptop:

    sshfs bravel@sftp.nsls2.bnl.gov:/nsls2/data/bmm ~/mnt/bmm -o follow_symlinks

    and this to unmount the data folder

    fusermount -u mnt/bmm

4.1.2. The Short Version#

Executive Summary

  1. Connect to sftp.nsls2.bnl.gov in your sftp client

  2. Authenticate using your BNL username/password and DUO two-factor authentication

  3. Navigate to /nsls2/data/bmm/proposals/, then to the cycle folder corresponding to the date of your experiment, then to the folder with your proposal number. So, something like /nsls2/data/bmm/proposals/2024-2/pass-333333.

  4. Transfer your data to your local computer.

If you preserve the folder structure from the remote host, the the dossier files (Section 12.4) will work as expected.

The assets folder contains raw image and HDF5 from your experiment. Those files will have database-friendly but user-unfriendly names. The HDF5 files are rather large and will take some time to download. The can skip downloading the assets folder if you do not plan on using the HDF5 files directly.

4.1.3. A Guide with Pictures#

What follows is a guide with screenshots of using FileZilla to connect to the SFTP download site and begin downloading data.

To begin, open your sftp client. Here is FileZilla at startup. For FileZilla, click on the File menu, then click on Site Manager.

_images/filezilla_startup.png

Fig. 4.1 FileZilla startup. Go to the Site Manager to establish a new location.#

In the site manager, click on the “New site” button and fill in the details as shown below. Select the SFTP protocol, enter sftp.nsls2.bnl.gov as the Host. The correct port number is 22, but you can usually leave that blank. 22 is the default port for the sftp protocol.

Finally, select “Interactive” as the logon type. That will tell FileZilla to prompt you for both user name and two-factor authentication.

_images/filezilla_site_manager.png

Fig. 4.2 Fill in the site manager with the location and logon type for the NSLS2 data center.#

Click OK to finish this configuration, then connect to the host.

_images/filezilla_connect.png

Fig. 4.3 Select the NSLS2 host from the drop-down list and click to connect.#

Connecting to the NSLS2 SFTP host will open up the password entry dialog.

_images/filezilla_password.png

Fig. 4.4 Enter your BNL password and click OK.#

After entering your password, you will be prompted for two factor authentication. In the “Password” box, type 1 and hit OK. Then go to your phone and accept the DUO push.

If you use a Yubikey, click on the “Password” box and touch the button on your Yubikey.

Once you have completed the DUO push, you will be able to navigate on the remote site. Click your way to /nsls2/data/bmm/ as shown below.

_images/filezilla_remote.png

Fig. 4.5 Navigate down to the BMM proposals area on the SFTP server.#

Click into proposals then into the folder for the cycle in which your experiment happened, then into the folder for your proposal number:

_images/filezilla_folder.png

Fig. 4.6 Navigate into the folder for your proposal and the cycle in which it ran.#

Now select the data files you want to transfer. You may select multiple files or even entire folders.

_images/filezilla_queue.png

Fig. 4.7 Select some or all of your data and add it to the queue.#

Click on the transfer button at the top of the screen to initiate the transfer. At the beginning of the transfer, you will have to re-authenticate yourself.

_images/filezilla_transfer.png

Fig. 4.8 Click the transfer button to download your data. You may need to re-authenticate at the start of transfer.#

Your data is now on your computer. Yay!

4.2. Accessing data with Globus#

Data volumes at BMM are such that sftp is usually easier and more efficient than using Globus. We recommend that you use sftp to access your data. However, Globus is an option.

To use Globus, you must transfer data to a Globus endpoint at your institution to which you have access. Alternately, you can run Globus Connect Personal (GCP) on your own computer. Follow the download and installation instructions and start an instance of GCP on your computer.

Once you have identified either an institutional endpoint or you have GCP running, point your web browser at http://globus.nsls2.bnl.gov/.

In the remote panel on the left side of the page, navigate to your proposal directory, which will be something like /nsls2/data/bmm/proposals/2024-3/pass-123456, where you would replace 2024-3 with the operations cycle of your visit to BMM and replace 123456 with your experiments proposal number.

In the local panel on the right side of the page, navigate to the location to which you want to download your data.

Select the data (or data folder) you wish to download and hit the start button above the remote folder.

4.3. Accessing data from the beamline computers#

Under the new data security regime, the beamline computer does not have normal access to your data. This is because all users run their experiment as the beamline operator. If the beamline operator – xf06bm – could see data, than any user could look at any other user’s data.

Instead, data are stored on central storage with read permission granted to everyone named on the user proposal. In this way, data are secured from other users and access to the data requires authentication.

To look at your data while at the beamline, do the following

  • Open a terminal window. Normally a terminal window with a white background is open on screen and intended for this purpose. bsui is typically run from a window with a black background, so the white background is meant as a visual cue indicating that it is the place for data access.

  • In that terminal window type

    su - <username>

    replacing <username> with your actual user name. Enter your password and respond to DUO push.

  • cd to /nsls2/data3/bmm/proposals/2024-2/pass-123456, replacing 2024-2 with the cycle of your visit and 123456 with your proposal number.

athena can be launched from the command line. The best way to do this is to type

dathena > /dev/null 2&>1 &

at the command line. That incantation will suppress spurious screen messages and put athena into the background so you can continue using the command line. From there, simply use athena’s File menu to load data from your proposal folder.

4.4. Using the VDI virtual Desktop#

Todo

Details needed

4.5. Accessing data via Tiled#

Todo

Details needed

4.6. Accessing data via Jupyter#

Todo

Details needed

4.7. Why is data security important?#

For those who have been coming to NSLS-II over the last decade, this new emphasis on data security might be a bit surprising. In short, the new data security model is consistent with Department of Energy data policies.

Recently, there were a pair of incidents involving accidental leaks of sensitive synchrotron data to unauthorized parties. This sort of violation of DOE policy can have an impact on the authorization to operate NSLS-II as a user facility. Safe operations of the facility includes data security.

As a result, our Data Science and Systems Integration team at NSLS-II has been begun moving the beamlines to a data acquisition model that includes sounds data security practices. BMM volunteered to be an early adopter of the new data security practices. We now provide an excellent user experience at BMM that also includes secure data management.


Contents