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Hyperspace

hypercritical.co

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Re: Hyperspace

#35

Earlier quoted context omitted.

You are complaining that it can’t instantaneously perform a complete scan of your disk, and then attributing malicious intent to this lack of magic instant scanning technology. What are we even doing here. The knee-jerk conspiratorial foolishness on this site is completely off the deep end.

No, I'm complaining that it doesn't ask me to pay before it takes my time to perform a complete scan of my disk (ideally before it even gives me a download of the app). We both know it does so intentionally, and we also know exactly what the intent is.

No we don't know this. And in fact you can listen to the Accidental Tech Podcast at length to hear him thinking through the current design at length.

Re: Hyperspace

#38
post #24

Earlier quoted context omitted.

It's a CoW (copy-on-write) file, it sounds like.

Yes, but it sounds like it's more fine-grained than just the file-level. So even if you change part of one copy, the remaining unchanged subpieces are still shared, iiuc.

CoW deduplicates at the block level. Unless you rewrite the whole file, the untouched blocks will remain common between them and only different blocks will be allocated separately.

Continuous block level deduplication is resource intensive and not a great fit unless space is at a high premium.

Offline block deduping is interesting though, but only for solid state storage. For hard disks it’s a nightmare.

Re: Hyperspace

#39

Seems useful for s3 buckets. I suppose a script that watches for new objects, calculates its sha256 and stores that in a DB, then checks for duplicate hashes would be a fairly trivial task. Though s3 doesn’t support symbolic links so accounting would need to be handled by server side code.

While the idea of data-deduplication does apply everywhere, this specifically depends on the APFS CoW data feature, so it's not applicable outside of macOS (or APFS Volumes)

The same concepts exist in ZFS, BtrFS and, IIRC, XFS.
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