5 ms·

In the last couple of version, updates are no longer differentials but full OS updates. They are shipped as a single signed package that is loaded into one of t

In the last couple of version, updates are no longer differentials but full OS updates. They are shipped as a single signed package that is loaded into one of the protected volumes of the disk. This is supposed to be a security measure to prevent compromises of components of the OS. The downside is big slow updates. Hopefully they work on that and do more like the differential updates that they use for iOS.

yjftsjthsd-h 5y ago
They could still apply a tiny patch and then checksum the whole thing, surely?
- kaba0 5y ago
  Just divide the whole thing into read-only units and reuse the unchanged ones, a la nixos.
- dymk 5y ago
  And if the checksum fails, what then?
  - howinteresting 5y ago
    Use a Merkle tree.
  - wazzaps 5y ago
    Maybe checksum before updating? Or revert the patch if it fails?
  - yjftsjthsd-h 5y ago
    Then abort the update? I'm not objecting to A/B partitions or filesystem snapshots or boot environments or however you want to implement it, I'm just saying that you can reconstruct the install image on the machine rather than downloading the whole thing over the wire.
  - waterhouse 5y ago
    Then fall back to downloading the full OS image. Then the worst case would be about the same as today, while the common (99.9%+) case would be fast and bandwidth-cheap. (Optimization: hash tree, figure out which specific files are broken and download only those.)
maxgashkov 5y ago
iOS updates are not exactly fast either. I've never seen latest iPad or iPhone updating in less than ~10 minutes, even for minor changes with the ~200-300 Mb update size.
vinay427 5y ago
To be fair, iOS updates also feel ancient compared to the Android live-update method which just requires a slightly longer reboot. On Android, I sometimes ended up on major releases and didn’t even notice because it just showed up upon my next reboot. On iOS I’m stuck without a phone for 10-15 minutes, which isn’t usually a problem when planned but feels rather archaic. To emphasize, this isn’t really a serious issue for most users, I’d imagine. I just wouldn’t want to see this as the model for improved Mac updates.

yjftsjthsd-h 5y ago

They could still apply a tiny patch and then checksum the whole thing, surely?

kaba0 5y ago
Just divide the whole thing into read-only units and reuse the unchanged ones, a la nixos.
dymk 5y ago
And if the checksum fails, what then?
- howinteresting 5y ago
  Use a Merkle tree.
- wazzaps 5y ago
  Maybe checksum before updating? Or revert the patch if it fails?
- yjftsjthsd-h 5y ago
  Then abort the update? I'm not objecting to A/B partitions or filesystem snapshots or boot environments or however you want to implement it, I'm just saying that you can reconstruct the install image on the machine rather than downloading the whole thing over the wire.
- waterhouse 5y ago
  Then fall back to downloading the full OS image. Then the worst case would be about the same as today, while the common (99.9%+) case would be fast and bandwidth-cheap. (Optimization: hash tree, figure out which specific files are broken and download only those.)

maxgashkov 5y ago

iOS updates are not exactly fast either. I've never seen latest iPad or iPhone updating in less than ~10 minutes, even for minor changes with the ~200-300 Mb update size.

vinay427 5y ago

To be fair, iOS updates also feel ancient compared to the Android live-update method which just requires a slightly longer reboot. On Android, I sometimes ended up on major releases and didn’t even notice because it just showed up upon my next reboot. On iOS I’m stuck without a phone for 10-15 minutes, which isn’t usually a problem when planned but feels rather archaic. To emphasize, this isn’t really a serious issue for most users, I’d imagine. I just wouldn’t want to see this as the model for improved Mac updates.