9 comments

  • tempay3 hours 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 CASTOR is the old system that has since been replaced by the CERN Tape Array since ~2020: <a href="https:&#x2F;&#x2F;cta.web.cern.ch&#x2F;cta&#x2F;" rel="nofollow">https:&#x2F;&#x2F;cta.web.cern.ch&#x2F;cta&#x2F;</a><p>This is mentioned on the page but it’s easy to miss.<p>For the current status of tape storage at CERN see: <a href="https:&#x2F;&#x2F;indico.cern.ch&#x2F;event&#x2F;1471803&#x2F;contributions&#x2F;6967379&#x2F;attachments&#x2F;3281280&#x2F;5863828&#x2F;2026-05-26_CHEP_Archiving60PBperMonthToTape_jleduc.pdf" rel="nofollow">https:&#x2F;&#x2F;indico.cern.ch&#x2F;event&#x2F;1471803&#x2F;contributions&#x2F;6967379&#x2F;a...</a><p>For reference, most disk storage for physics data uses an in-house solution called EOS: <a href="https:&#x2F;&#x2F;eos-web.web.cern.ch&#x2F;eos-web&#x2F;" rel="nofollow">https:&#x2F;&#x2F;eos-web.web.cern.ch&#x2F;eos-web&#x2F;</a>
    • bfkwlfkjf3 hours 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&#x27;s kept on disk and what&#x27;s kept on tape
      • tempay3 hours 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_bristow3 hours ago
        The linked page seems to think it does.<p>&quot;As of June 29th 2020, CTA, the CERN Tape Archive, started to be operated as the successor of CASTOR and gradually replaced it.&quot;
  • john_strinlai4 hours ago
    looks like the image on the right is broken, but it is supposed to be: <a href="https:&#x2F;&#x2F;cta.web.cern.ch&#x2F;cta&#x2F;assets&#x2F;images&#x2F;namespace_statistics.png" rel="nofollow">https:&#x2F;&#x2F;cta.web.cern.ch&#x2F;cta&#x2F;assets&#x2F;images&#x2F;namespace_statisti...</a><p>(looks like this submission uses <a href="https:&#x2F;&#x2F;castor.web.cern.ch&#x2F;content&#x2F;home.html" rel="nofollow">https:&#x2F;&#x2F;castor.web.cern.ch&#x2F;content&#x2F;home.html</a> instead of <a href="https:&#x2F;&#x2F;castor.web.cern.ch&#x2F;castor&#x2F;" rel="nofollow">https:&#x2F;&#x2F;castor.web.cern.ch&#x2F;castor&#x2F;</a> the second link does not have the broken image)
  • Melatonic3 hours ago
    This is actually super useful for real world stuff. Thanks for this.<p>Tape is boring but when an intern &#x2F; AI &#x2F; tectonic plate accidently destroys your database setup it is a huge lifesaver<p>Anybody know what these fancy Oracle tapes are? Is it just their implementation of a regular standard?
    • linksnapzz50 minutes ago
      If it&#x27;s Oracle Tape, it&#x27;s proprietary T10000-series 1&#x2F;2in linear tape and associated drives, that they got when they absorbed Sun (and Sun got when they bought StorageTek). Multiple vendors made tape media for these, but they were not compatible w&#x2F; LTO tape nor the IBM 3590-series enterprise tape format.
    • tempay3 hours ago
      See this conference talk from last week: <a href="https:&#x2F;&#x2F;indico.cern.ch&#x2F;event&#x2F;1471803&#x2F;contributions&#x2F;6967379&#x2F;" rel="nofollow">https:&#x2F;&#x2F;indico.cern.ch&#x2F;event&#x2F;1471803&#x2F;contributions&#x2F;6967379&#x2F;</a><p>There isn’t a recording but slides at linked from that page.
  • perlgeek3 hours ago
    &quot;Castor&quot; 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.<p>Wouldn&#x27;t have been my choice for a software project :-)
    • tempay3 hours ago
      It’s also French for Beaver which is more likely the origin of the name.
      • rzzzt3 hours ago
        It&#x27;s also Latin and Greek for beaver which is more likely the origin of the name.
        • tempay3 hours ago
          Latin and Greek aren’t one of the working languages at CERN (French and English are)
  • boznz3 hours 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!
  • dokyun2 hours ago
    Wonder how this compares to Venti[1]. It looks a lot more complicated (not really a good thing).<p>[1]: <a href="https:&#x2F;&#x2F;doc.cat-v.org&#x2F;plan_9&#x2F;4th_edition&#x2F;papers&#x2F;venti&#x2F;" rel="nofollow">https:&#x2F;&#x2F;doc.cat-v.org&#x2F;plan_9&#x2F;4th_edition&#x2F;papers&#x2F;venti&#x2F;</a>
    • linksnapzz1 hour ago
      You could use tape as a backing for Venti arenas; don&#x27;t know if anyone ever did so. The original Bell Labs fileserver used an MO jukebox for WORM archives, which today LTFS tape is a pretty close approximation of.
  • mrlonglong3 hours ago
    They now have over an exabyte worth of data on tapes.
  • bitbytebane3 hours ago
    [dead]
  • Lapsa3 hours ago
    [dead]