EOS workshop

Session

CTA

3

3 Mar 2021, 08:00

Conveners

CTA: Tape Service

• Oliver Keeble (CERN)

CTA: Tape Service

• Oliver Keeble (CERN)

Description

All about CTA

14. EOS+CTA WorkFlows: Tape Archival and Retrieval

Michael Davis (CERN)

03/03/2021, 08:00

The CERN Tape Archive (CTA) is the tape back-end to EOS. EOS provides an event-driven interface, the WorkFlow Engine (WFE), which is used to trigger the processes of archival and retrieval. When EOS is configured with its tape back-end enabled, the CREATE and CLOSEW (CLOSE Write) events are used to trigger the archival of a file to tape, while the PREPARE event triggers the retrieval of a file...

16. Running an EOS instance with tape on the back

Julien Leduc (CERN)

03/03/2021, 08:20

An EOSCTA instance is an EOS instance commonly called a tape buffer configured with a CERN Tape Archive (CTA) back-end.

This EOS instance is entirely bandwidth oriented: it offers an SSD based tape interconnection, it can contain disks if needed and it is optimized for the various tape workflows.

This talk will present the specific details of the EOS tape buffer tweaks and the Swiss...

33. AARNet CTA Investigations

David Jericho (AARNet)

03/03/2021, 08:40

15. CTA best practices for data taking workflows

Volodymyr Yurchenko (National Academy of Sciences of Ukraine (UA))

03/03/2021, 09:20

There is significant diversity in the Data Acquisition (DAQ) systems of the non-LHC experiments supported at CERN. Each system can potentially have its own data taking software and helper scripts, and each can use their preferred data transfer commands and apply different checks and retry policies. The task of the CERN Tape Archive (CTA) team is to provide support for all of these different...

9. A brief overview of the CTA mount scheduling logic

Cedric Caffy (CERN)

03/03/2021, 09:40

Accessing data in a tape archival system can be costly in terms of time. The time taken to mount a tape into a drive, to position the tape head to a file and to unmount the tape when this file has been read can take more than 2 minutes.

A tape drive cannot be used to archive or retrieve data during the mounting and unmounting of a tape. We therefore need a solution to avoid mounting a tape...

10. ALICE and the CTA Garbage Collectors

Steven Murray (CERN)

03/03/2021, 10:00

In the standard layout of an EOSCTA deployment there are two SSD buffers in front of the tape drives. One is called the “default” space and is used for writing files to tape and the other is called the “retrieve” space and is used for reading them back. These buffers prevent direct file transfers between HDDs and tape drives. Such direct transfers would suffer from the unacceptable performance...