Swestore-dCache

From SNIC Documentation
Revision as of 15:13, 20 January 2017 by Jens Larsson (NSC) (talk | contribs) (→‎Register your eScience client certificate in SUPR (for all users))
Jump to: navigation, search


Swestore is Research Data Storage Infrastructure operated by the Swedish National Infrastructure for Computing (SNIC).

The resources provided by Swestore are made available through open procedures such that the best Swedish research is supported and new research is facilitated. The purpose of Swestore allocations, granted by Swedish National Allocations Committee (SNAC), is to provide large scale data storage for “live” or “working” research data, also known as active research data.

Due to the VR funding, the free allocations on Swestore have some usage limitations.

  • Swestore is NOT supposed to be used for backups and such requests for allocation will be rejected. Please, check with your university (home institution/organisation) IT department about backup services, strategies and policies in place. If such services do not exist or if you can’t access them for different reasons, please contact us at support@swestore.se;
  • Swestore is NOT supposed to be used as archiving service, long-term storage or repository for “static” data. Once data is no longer in the process of change, and decision on which data should be retained shared and/or preserved has been taken, data should be moved toward appropriate data services. The higher education institutions are responsible for archiving and long-term preservation of research data produced by researchers employed by them;
Glossary
Active (Research) data
is data that is being worked on as part of research project and therefore subject to change. The files containing data will need to be accessed and amended or updated as new data is gathered or processed.
Static (Research) data
is data that is no longer in the process of change and it can be prepared for preservation and reuse.
Backup
is a copy of the digital data to be stored and used as a replacement in case the main copy is either deleted or corrupted.
Archive
is a service to record, organise, and store (digital) items in optimal conditions, with standardised labelling to ensure their longevity and continued access. The service is based on application of metadata, archiving policies, records management, and digital preservation actions. Archivists make decisions on selection and retention of items which are usually governed by supporting policies.


Swestore is distributed across the SNIC centres C3SE, HPC2N, Lunarc, NSC and Uppmax. Data is stored in two copies with each copy at a different SNIC centre. This enables the system to cope with a multitude of issues ranging from a simple crash of a storage element to losing an entire site while still providing access to the stored data.

One of the major advantages to the distributed nature of Swestore is the excellent aggregated transfer rates possible. This is achieved by bypassing a central node and having transfers going directly to/from the storage elements if the selected transfer protocol allows it. Swestore can achieve aggregated transfer rates in excess of 100 Gigabit per second, but in practice this is limited by connectivity to the end user, each university or a limited number of files (typically max 1 Gbit/s per file/connection).

To protect against silent data corruption the dCache storage system checksums all stored data and periodically verifies the data using this checksum.

The dCache system does NOT yet provide protection against user errors like inadvertent file deletions.

Getting access to Swestore

These steps are required for all PI:s and users of Swestore regardless of how the storage area later is accessed.

Apply for storage (for the PI)

All normal Swestore projects are managed using the SNIC User and Project Repository portal, SUPR. Please follow the instructions on the Apply for storage on Swestore page to apply for storage.

Acquire an eScience client certificate (for all users)

Swestore user authentication is currently done by user/client certificates. All project members needs to acquire a certificate by following the instructions on the Grid certificates page. This step can be performed while waiting for the storage application to be approved. If you already have a valid grid or eScience certificate you don't need to acquire another one.

Manage your eScience client certificate (for all users)

There are multiple suppliers of certificates. Depending on the supplier this step varies a bit.

For Digicert certificates
If intending to access Swestore from a SNIC resource, please make sure you also export the certificate, transfer it to the intended SNIC resource and prepare it for use with grid tools.
For Nordugrid certificates
Please make sure to also install your client certificate in your browser.

Register your eScience client certificate in SUPR (for all users)

All project members have to register in SUPR and be added to the approved project by the PI. All users also have to register their certificate in SUPR. This information is used by Swestore to authenticate the users when accessing the storage area. Registering the certificate is easy though. Make sure your certificate is stored in your browser, log in to SUPR , click "Personal Information" in the left menu, click "Register Client Certificate" and follow the instructions. Please wait for up to 10 minutes for this information to be distributed to Swestore.

Using Swestore

Download and upload data

From the command line

There are several command line tools capable of using the protocols provided by Swestore. For interactive usage on SNIC clusters we recommend using the ARC tools which should be installed on all SNIC resources.

As an integration point for building scripts and automated systems we suggest using the curl program and library.

ARC
Please see the instructions for Accessing Swestore with the ARC client. Recommended method when logged in on SNIC resources.
lftp
See the instructions for Accessing Swestore with lftp.
cURL
Please see the instructions for Accessing Swestore with cURL. We suggest using this as integration point for building scripts and automated systems.
globus-url-copy
Please see the instructions for Accessing Swestore with globus-url-copy.
gfal2
(not documented yet)
https://duck.sh/
Command-line client for Windows/macOS (not documented yet)

Using a GUI client

Graphical User Interface (GUI) clients are known to work on some operating systems.

Cyberduck
Please see the instructions for Accessing Swestore using Cyberduck Recommended method on Windows and macOS

From a web browser

Swestore is accessible in your web browser as a simple directory index interface at https://webdav.swestore.se/. To browse private data you need to have your certificate installed in your browser (see above). Projects are organized under the /snic directory as https://webdav.swestore.se/snic/YOUR_PROJECT_NAME/.

Enabled access protocols

A design criteria for Swestore is to provide the storage over a number of standardized and public protocols. There is no vendor specific client needed for access.

GridFTP
Also called gsiftp. Well supported within Swestore.
Features: Transfer checksums. Writes goes directly to storage pools for high speed transfers.
Access URL: gsiftp://gsiftp.swestore.se/
HTTP/WebDAV
Contender for being the recommended protocol for Swestore.
Features: Direct support in web browsers. Redirected reads and writes if special url is used and client supports it.
Access URL: http://webdav.swestore.se/ (unauthenticated, read-only, non-redirected)
Access URL: https://webdav.swestore.se/ (authenticated, read-write, non-redirected)
Access URL: http://webdav.swestore.se:1080/ (unauthenticated, read-only, redirected)
Access URL: https://webdav.swestore.se:1443/ (authenticated, read-write, redirected)
NFSv4.1
Used by some communities, not recommended for general use
SRM - Storage Resource Manager
Used by some communities, not recommended for general use.
Access URL: srm://srm.swegrid.se/
Xrootd
Used by some communities, not recommended for general use
DCAP
Used by some communities, not recommended for general use

Tools and scripts

There exists a number of tools and utilities developed externally that can be useful. Here are some links:

Slides and more

Slides and material from seminar for Lund users on April 18th

Usage monitoring

Support

If you have any issues using Swestore, please do not hesitate to contact support@swestore.se.

Retrieved from "https://docs.snic.se/w/index.php?title=Swestore-dCache&oldid=6673"