Castor: CERN Advanced STORage Manager

9 comments

• tempay 1 hour ago
  I’m a little confused by this submission. CASTOR is the old system that has since been replaced by the CERN Tape Array since ~2020: https://cta.web.cern.ch/cta/

  This is mentioned on the page but it’s easy to miss.

  For the current status of tape storage at CERN see: https://indico.cern.ch/event/1471803/contributions/6967379/a...

  For reference, most disk storage for physics data uses an in-house solution called EOS: https://eos-web.web.cern.ch/eos-web/

  [-]
  • bfkwlfkjf 43 minutes ago
    Does tape array replace castor? Just from the names it sounds like tape array is the actual storage, and castor is an abstraction that automatically decides what's kept on disk and what's kept on tape
    [-]
    • tempay 23 minutes ago
      The abstraction isn’t really a thing any more. It was a nice idea but in practice it’s an operational nightmare not knowing if data is available and for how long it will be. For reference staging can take days during intense activity and you don’t want to loose performance randomly seeking around and switching between tapes.
    • sam_bristow 20 minutes ago
      The linked page seems to think it does.

      "As of June 29th 2020, CTA, the CERN Tape Archive, started to be operated as the successor of CASTOR and gradually replaced it."
• john_strinlai 2 hours ago
  looks like the image on the right is broken, but it is supposed to be: https://cta.web.cern.ch/cta/assets/images/namespace_statisti...

  (looks like this submission uses https://castor.web.cern.ch/content/home.html instead of https://castor.web.cern.ch/castor/ the second link does not have the broken image)
• Melatonic 1 hour ago
  This is actually super useful for real world stuff. Thanks for this.

  Tape is boring but when an intern / AI / tectonic plate accidently destroys your database setup it is a huge lifesaver

  Anybody know what these fancy Oracle tapes are? Is it just their implementation of a regular standard?

  [-]
  • tempay 1 hour ago
    See this conference talk from last week: https://indico.cern.ch/event/1471803/contributions/6967379/

    There isn’t a recording but slides at linked from that page.
• perlgeek 1 hour ago
  "Castor" was the name of a storage system used for transporting nuclear waste in Germany. There were quite a few protests against shipping nuclear waste through the country.

  Wouldn't have been my choice for a software project :-)

  [-]
  • tempay 1 hour ago
    It’s also French for Beaver which is more likely the origin of the name.
    [-]
    • rzzzt 55 minutes ago
      It's also Latin and Greek for beaver which is more likely the origin of the name.
      [-]
      • tempay 30 minutes ago
        Latin and Greek aren’t one of the working languages at CERN (French and English are)
• dokyun 10 minutes ago
  Wonder how this compares to Venti[1]. It looks a lot more complicated (not really a good thing).

  [1]: https://doc.cat-v.org/plan_9/4th_edition/papers/venti/
• boznz 1 hour ago
  The various CERN web pages such as this were a treasure trove of information when I was working on my last novel. I actually included a few paragraphs on Castor thinking of using it as a side-plot, but my editor cut the plot out along with a few other technical niceties. Sigh!
• mrlonglong 41 minutes ago
  They now have over an exabyte worth of data on tapes.
• bitbytebane 49 minutes ago
  [dead]
• Lapsa 17 minutes ago
  [dead]