Posts on dCache.org

20th International dCache Workshop

Mon, 16 Feb 2026 11:05:17 +0100

We are pleased to announce the 20th International dCache Workshop 2025! The workshop will be held in person from May 6 to May 7, 2026, at Nikhef in Amsterdam.

https://indico.nikhef.nl/event/7562/

As always, we will present upcoming developments and technologies related to dCache, as well as those influencing its ecosystem. We also welcome contributions from the community—whether you have a unique configuration, a specific user community use case, or experience with new hardware, we’d love to hear from you!

If you have something to share or are interested in a particular topic, let us know—your input is invaluable!

Please contact us for workshop-related questions and suggestions using workshopԹdcache.org.

dCache turned 25!

Tue, 16 Sep 2025 10:15:18 +0200

On the 16th of September 2000, at the Computer User Committee at DESY, a new project, A Homogeneous Distributed Storage Environment for Physics Data Processing, was presented. Its main objectives were to address storage system concerns after HERA and Tevatron accelerator upgrades at DESY and Fermilab.

The new system had the following goals:

Optimized usage of existing tape drives through transfer rate adaptation.
Support for slower, cheaper drive technologies without reducing overall performance.
Improved utilization of robot systems by coordinating read and write requests.
Better use of network bandwidth by locating data at the most suitable site.
Direct data access without requiring explicit staging.
Uniform access methods for data, independent of its storage medium.
A unified system view, even without the backend HSM, presenting a large data store with a unique namespace and standardized access methods. Valuable data would remain safely on disk until an HSM copy was created. Transfers to the HSM could be policy-driven or triggered manually.
A collaborative effort, ensuring more efficient use of manpower and guaranteeing long-term support and maintenance of the software.

This vision led to the official approval of the dCache project, cementing a lasting collaboration between Fermilab and DESY.

Since then, dCache is not only used by Fermilab and DESY, but has become a major storage system deployed at many sites around the world.

During the past 25 years, we have always tried to address new challenges as soon as they showed up on the horizon: GRID computing, distributed deployments, new authentication methods and access protocols. And while dCache is open to new technologies, we have always advocated for standard solutions. Today, dCache can expose data through standard WebDAV or NFSv4.1 protocols, protect in transit data with TLS, manage the user base in an LDAP and authenticate via OAuth2 or OpenID-Connect.

But none of this journey would have been possible without our users and collaborators. Their trust, feedback, and ambitious use cases have continuously pushed us to innovate, adapt, and grow.

The journey so far has been remarkable — but even greater challenges and opportunities are still to come.

🎉 Happy Birthday, dCache! 🚀

19th International dCache Workshop

Sun, 17 Mar 2024 11:05:17 +0100

We are pleased to announce the 19th International dCache Workshop 2025! The workshop will be held in person from May 20 to May 21, 2025, at CC-IN2P3 in Lyon.

https://indico.desy.de/e/dcache-uw19

If you have something to share or are interested in a particular topic, let us know—your input is invaluable!

Please contact us for workshop-related questions and suggestions using workshopԹdcache.org.

18th International dCache Workshop

Mon, 05 Feb 2024 17:05:17 +0100

We are happy to announce the 18th International dCache workshop 2024 will take place from 2024-06-06 to 2024-06-07 in person and hosted by DESY-Hamburg.

https://indico.desy.de/e/dcache-ws18

As usual we will present forthcoming developments and technologies, both provided by and influencing dCache. However, we are always happy to include presentations from you, especially if you have a special configuration, user community or use case, or experience with new hardware. If you have something to share with us or have an interest in a particular topic - hands up!

Please contact us for workshop related questions and suggestion using workshopԹdcache.org.

17th International dCache Workshop

Sat, 04 Feb 2023 10:05:17 +0100

We are happy to announce the 17th International dCache Workshop in Berlin, Germany from 2023-05-31 to 2023-06-01. The workshop will take place in person and hosted by HTW Berlin - University of Applied Sciences.

https://indico.desy.de/e/dcache-ws17

Please contact us for workshop related questions and suggestion using workshopԹdcache.org.

Vulnerability in PostgreSQL server

Tue, 24 May 2022 11:18:28 +0200

We get contacted by EGI security to comment on PostgreSQL vulnerability CVE-2022-1552.

The dCache itself is not affected. Moreover, the most of the installations do not share postgresql used by dCache with other services, thus there are no other users ‘having permission to create non-temp objects’ on the same DB.

Nonetheless, we encourage sites to update the postgresql servers to recommended versions at the next possible maintenance slot.

16th International dCache Workshop

Thu, 24 Mar 2022 23:05:17 +0100

We are happy to announce the 16th International dCache Virtual Workshop.

https://indico.desy.de/event/33984/

We have reserved two slots: one May 24 from 16:00 to 17:30 CEST (9:00 - 10:30 AM CST) for the dCache project report and a second one, May 25 from 16:00 to 17:30 CEST (9:00- 10:30 AM CST) for sites.

Please contact us for workshop related questions and suggestion using workshopԹdcache.org.

Log4j 1.2 Vulnerability

Fri, 28 Jan 2022 17:12:59 +0100

A critical security vulnerability https://nvd.nist.gov/vuln/detail/CVE-2022-23307 has been identified in the “Apache Apache Chainsaw” library. Prior to Chainsaw V2.0 Chainsaw was a component of Apache Log4j 1.2.x where the same issue exists. This has raised concerns among many dCache admins, who have contacted us either directly or by sending a message to securityԹdcache.org. Thanks for that!

Log4j in dCache

dCache uses logback as the default logging solution and does not distribute the Log4j library with officially released packages. It is therefore not affected.

Log4j in ZooKeeper

Like many Java based projects, ZooKeeper and Apache Kafka use Log4j-1.2 as their logging library.

There are to options, how sites deploy zookeeper for dCache: ether as dCache cell (don’t do this, unless you have a good reason for that) or as a standalone zookeeper cluster.

If you use embedded zookeeper, you can stop reading here. dCache forces all calls to log4j to be redirected to logback. Your zookeeper is not affected.

For the sites, that use zookeeper rpms build by dcache.org we have build the zk-3.5.8-3 package with corresponding fix.

For sites that use rpms built by others or use tarballs provided by Apache Foundation can either switch to rpms built by dcache.org or apply the workaround manually:

zip -q -d /usr/lib/zookeeper/lib/log4j* org/apache/log4j/chainsaw/*

NOTE: the path to log4j jar might be different and depends on packaging, zookeeper version and distribution.

Log4j Vulnerability

Sat, 11 Dec 2021 22:49:52 +0100

A critical security vulnerability CVE-2021-44228 has been identified in the popular “Apache Log4j 2” library (2.x <= 2.15.0-rc1). This has raised concerns among many dCache admins, who have contacted us either directly or by sending a message to securityԹdcache.org. Thanks for that!

Log4j in dCache

dCache uses logback as the default logging solution and does not distribute the Log4j library with officially released packages. It is therefore not affected.

Log4j in ZooKeeper and Kafka

Like many Java based projects, ZooKeeper and Apache Kafka use Log4j as their logging library. However, they both depend on log4j-1.2.x, which is not vulnerable to this CVE.

Log4j in the dCache project infrastructure

We are currently checking the entire dCache project infrastructure for the presence of vulnerable versions of the Log4j library. This work is ongoing.

The Workshop slides are online

Thu, 03 Jun 2021 16:09:29 +0200

We hope that you enjoyed the 15 dCache international workshop as we did. Thanks a lot to the all presenters and participants for provided information, comments and discussions. There ware lot of information that you can revisit by looking at the slides that are available online.

15th International dCache Workshop

Fri, 09 Apr 2021 17:05:16 +0200

We are happy to announce the 15th International dCache Virtual Workshop.

https://indico.desy.de/event/29564/

We have reserved two slots: one Jun 1 from 16:00 to 17:30 CEST (9:00 - 10:30 AM CST) for the dCache project report and a second one, Jun 2 from 16:00 to 17:30 CEST (9:00- 10:30 AM CST) for sites.

Please contact us for workshop related questions and suggestion using workshopԹdcache.org.

Mini-Workshop on systemd and dCache

Tue, 03 Nov 2020 15:40:49 +0100

dCache version 6.2 comes with full systemd integration. However, this transition required a significant changes in the way how dCache is deployed and operated.

On November 18, 16:00-17:00 CET we would like to invite you to a mini-workshop on systemd implementation in dCache as well as to share experience from sites that already use dCache with systemd.

This will a Video meeting. The links to the connection details will be available soon.

Update

The workshop indico link

dCache is 20!

Mon, 31 Aug 2020 20:37:12 +0200

Optimized usage of existing tape drives due to transfer rate adaption.
Possible usage of slower and cheaper drive technology without overall performance reduction.
Optimized usage of the robot systems by coordinated read and write requests.
Better usage of network bandwidth by exploring the best location for the data.
No explicit staging required to access the data.
Access methods for data that would be unique, independent of its media location.
A view of the system, even without the backend HSM, as a huge data store with a unique namespace and standardized access methods. Care would be taken that valuable data reside on safe disks as long as no HSM copy exists. Backend storage to the HSM could be done regularly (policy based) or by manual intervention only.
A joint effort, making the use of manpower more efficient and guaranteeing continued support and maintenance of the developed software.

Thus the dCache project was officially approved, initiating a long standing collaboration between Fermilab and DESY on the development of a common storage solution.

Since then, dCache is not only used by Fermilab and DESY, but has become a major storage system deployed at many sites around the world.

During the past two decades, we have always tried to address new challenges as soon as they showed up on the horizon: GRID computing, distributed deployments, new authentication methods and access protocols. And while dCache is open to new technologies, we have always advocated for standard solutions. Today, dCache can expose data through standard WebDAV or NFSv4.1 protocols, protect in transit data with TLS, manage the user base in an LDAP and authenticate via OAuth2 or OpenID-Connect.

The road behind us is a long one, but we also have new challenges in front of us.

Happy Birthday, dCache!

Workshop

Sun, 31 May 2020 18:11:34 +0200

Once a year dCache developers, sysadmins and friends from around the world meet to exchange news, best practices and gossip. In the past those meetings were held in beautiful cities around the world such as Amsterdam, Madrid, Taipei, Hamburg and many more. Due to the current situation, this year’s meeting was held as a video conference on the 26th/27th of May in the afternoon hours.

The agenda and slides from the workshop are available on the Indico page.

Migrating to a new website engine

Sun, 31 May 2020 18:01:39 +0200

After almost two decades, the dCache.org web content has been migrated from regular HTML pages written by hand to a modern static site generator based on hugo with the Mainroad template.

This change will simplify the maintenance of the web pages and will allow developers to keep the content up-to-date. New pages and documentation can be added by simply dropping a file written in markdown format into the desired directory. The source code of the pages is available on GitHub and can be directly edited in a browser.

The new pages are following the responsive design concept, which makes them mobile device friendly.