# EOS+CTA WorkFlows: Tape Archival and Retrieval

- Institution: CERN
- Department: HEP Computing
- Speaker: Michael Davis
- Year: 2021
- Language: English
- Subjects: Computer science
- Source: [CERN](https://videos.cern.ch/record/3000333)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

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 from tape and the creation of a disk replica.

This talk will present the details of these tape-related workflows, including the state machine for the processes of archival and retrieval, and the metadata which is communicated between EOS and CTA..

0:00:00 Slide 1

0:01:55 Slide 2

0:03:50 Slide 3

0:05:45 Slide 4

0:07:39 Slide 5

0:09:34 Slide 6

0:11:29 Slide 7

0:13:23 Slide 8

0:15:18 Slide 9

0:17:13 Slide 10

0:19:08 Slide 11

## Lectures

1. [EOS+CTA WorkFlows: Tape Archival and Retrieval](https://invisiblenetwork.ai/learn/cern/3000333/b92b4b1d9151), 20 min (CERN's player)