5 ms·

Serious question: what value does filesystem checksumming offer for the average user who has no redundancy? I mean, it'll tell you that your only copy of a fil

by brigade 10y ago

Serious question: what value does filesystem checksumming offer for the average user who has no redundancy? I mean, it'll tell you that your only copy of a file got corrupted, but it'll still be corrupted...

liw 10y ago
It tells you that your file is corrupted. You can then restore from backups, re-download, or take some other corrective action, such as delete the file, reboot the machine, re-install the operating system, or play Quake 2 to test your RAM and graphics. Never underestimate the value of a reason to play Quake 2.
- Zardoz84 10y ago
  I remember when I played DooM to test and benchmark a computer...
radiowave 10y ago
The average user might have no redundancy, but they still ought to have a backup. Checksum failure tells them they need to restore. At the very least, a checksum failure might tell them (or the tech they're consulting) that they have a data problem, rather than, say, an application compatibility problem.
- XorNot 10y ago
  "Why is my machine crashing?" "Well, somelib.so is reporting checksum failures" is a much better experience then "weird, this machine used to be great but now it crashes all the time"
  - kartickv 10y ago
    somelib.so what? And what's a "checksum"? Error messages need to be comprehensible to the average user.
    - brokenmachine 10y ago
      "Error: Buy a new Mac."
      - kartickv 10y ago
        Assuming your intent is not to troll: "The file xyz.txt is corrupt. Click here to restore from a Time Machine backup."
  - astrange 10y ago
    Most all executable files are already codesigned, which is a better version of checksums, so it'd only help user data files.
- mindajar 10y ago
  Today you can verify backups on OS X with "tmutil verifychecksums", at least on 10.11. The UI to this could be improved, but user data checksums don't necessarily need to be a filesystem feature. On a single-disk device, the FS doesn't have enough information to do anything useful about corrupt files anyway.
  - vardump 10y ago
    > On a single-disk device, the FS doesn't have enough information to do anything useful about corrupt files anyway. Some filesystems can be configured to keep two or more copies of certain filesystem/directory/etc. contents. Two copies is enough information to do something useful.
comex 10y ago
Well, Apple is moving in the direction of syncing everything with iCloud - iCloud Drive has been around for a while, and Sierra adds the ability to sync the desktop and Documents folder; of course on top of long-existing things like photo sync. If the file was previously uploaded to iCloud, there is redundancy, and you definitely don't want to overwrite it with the corrupted version. How big an issue this is in practice I don't know.

by brigade 10y ago

liw 10y ago

It tells you that your file is corrupted. You can then restore from backups, re-download, or take some other corrective action, such as delete the file, reboot the machine, re-install the operating system, or play Quake 2 to test your RAM and graphics. Never underestimate the value of a reason to play Quake 2.

Zardoz84 10y ago
I remember when I played DooM to test and benchmark a computer...

radiowave 10y ago

The average user might have no redundancy, but they still ought to have a backup. Checksum failure tells them they need to restore. At the very least, a checksum failure might tell them (or the tech they're consulting) that they have a data problem, rather than, say, an application compatibility problem.

XorNot 10y ago
"Why is my machine crashing?" "Well, somelib.so is reporting checksum failures" is a much better experience then "weird, this machine used to be great but now it crashes all the time"
- kartickv 10y ago
  somelib.so what? And what's a "checksum"? Error messages need to be comprehensible to the average user.
  - brokenmachine 10y ago
    "Error: Buy a new Mac."
    - kartickv 10y ago
      Assuming your intent is not to troll: "The file xyz.txt is corrupt. Click here to restore from a Time Machine backup."
- astrange 10y ago
  Most all executable files are already codesigned, which is a better version of checksums, so it'd only help user data files.
mindajar 10y ago
Today you can verify backups on OS X with "tmutil verifychecksums", at least on 10.11. The UI to this could be improved, but user data checksums don't necessarily need to be a filesystem feature. On a single-disk device, the FS doesn't have enough information to do anything useful about corrupt files anyway.
- vardump 10y ago
  > On a single-disk device, the FS doesn't have enough information to do anything useful about corrupt files anyway. Some filesystems can be configured to keep two or more copies of certain filesystem/directory/etc. contents. Two copies is enough information to do something useful.

comex 10y ago

Well, Apple is moving in the direction of syncing everything with iCloud - iCloud Drive has been around for a while, and Sierra adds the ability to sync the desktop and Documents folder; of course on top of long-existing things like photo sync. If the file was previously uploaded to iCloud, there is redundancy, and you definitely don't want to overwrite it with the corrupted version. How big an issue this is in practice I don't know.