Swestore-dCache

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Swestore-dCache is distributed across the SNIC centres C3SE, HPC2N, Lunarc and NSC. 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.

Contents

Basic information

For basic information on how to apply for storage or become a member of an existing project, please check the main Swestore page.

Acquire and manage certificate (for users accessing with certificate authentication)

Certificate authentication is needed in some special cases, and more convenient for use in automation (ie. Robot certificates).

Some communities require certificate authentication and such users might already have a certificate, that certificate is likely good to use with Swestore.

If you need to use Certificate authentication, follow the instruction on the page Certificate Setup for 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 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.

Interactive tools
Best suited for interactive use with various support for directory listings, wildcards etc.
Currently no suitable tools to recommend
Command-line tools
These tools are also suitable for scripting or automation.
rclone
Supports multiple protocols.
Please see the instructions for Accessing Swestore with rclone.
cURL
Please see the instructions for Accessing Swestore with cURL. We suggest using this as integration point for building scripts and automated systems.
davix
Swestore-specific documentation not written yet. See upstream documentation at https://davix.web.cern.ch/davix/docs/master/
Use access URL: davs://webdav.swestore.se:1443/
ARC
Certificate authentication only. Supports multiple protocols.
Please see the instructions for Accessing Swestore with the ARC client.
gfal2
Certificate authentication only. Supports multiple protocols.
Swestore-specific documentation not written yet. See upstream documentation at https://dmc.web.cern.ch/projects/gfal-2/documentation
Use access URL: gsiftp://gsiftp.swestore.se/
https://duck.sh/
Command-line client for Windows/macOS/Linux (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 macOS
WinSCP
Please see the instructions for Accessing Swestore using WinSCP Recommended method on Windows

From a web browser

Swestore is accessible in your web browser as a simple directory index interface at https://webdav.swestore.se/.

Web browser access supports both username/password and certificate authentication.

Projects are organized under the /snic directory as https://webdav.swestore.se/snic/DIRECTORY_NAME/.

JavaScript WebDAV client

Swestore dCache can also be accessed in your browser, through a JavaScript client, over WebDAV at https://webdav.swestore.se/browser/ .

Legacy documentation

There are other clients/methods available, but not recommended for new deployments. See Category:Swestore user guide for a complete list of documentation.

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. Direct transfer from/to storage pools for high speed transfers.
Access URL: gsiftp://gsiftp.swestore.se/
HTTP/WebDAV
Contender for being the recommended protocol for Swestore.
Features: Support in web browsers. Supports direct transfer of files from/to storage pools improving performance (varying support in clients).
Authenticated access
This is the normal read-write access.
Access URL: https://webdav.swestore.se/ (non-redirected)
Access URL: https://webdav.swestore.se:1443/ (redirected)
Access URL: https://webdav.swestore.se:2443/ (redirected reads)
Unauthenticated read-only access
For special cases only.
Access URL: http://webdav.swestore.se/ (unauthenticated, read-only, non-redirected)
Access URL: http://webdav.swestore.se:1080/ (unauthenticated, read-only, redirected)
Access URL: http://webdav.swestore.se:2080/ (unauthenticated, read-only, redirected reads)
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

Usage monitoring

Support

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

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