[Bug 1958180] Re: "not in multiple of 0x10000" chkdsk errors for sparse files

[Jean-Pierre]

Nothing to be worried about, this is not a bug and the message is just a
technical warning. The chkdsk conclusion is "Windows has scanned the
file system and found no problems."

Since about 2016, Windows allocates space by chunks of multiple
clusters, but it still correctly processes files allocated by a single
cluster at a time. You need not make a copy to use it.

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https://bugs.launchpad.net/bugs/1958180

Title:
  "not in multiple of 0x10000" chkdsk errors for sparse files

Status in ntfs-3g package in Ubuntu:
  New

Bug description:
  In Ubuntu 21.10 using ntfs-3g 1:2017.3.23AR.3-3ubuntu5 I can create
  sparse files which result in the following messages from Windows 10
  21H2 disk scanning:

  Stage 1: Examining basic file system structure ...
  The allocated length 0x41000 is not in multiple of 0x10000 for attribute
  of type 0x80 and instance tag 0x1.

  The Windows GUI will say that the drive was scanned successfully with
  no errors, and I will need to look in Event Viewer to see this in
  scanning output. Repeated scans will not do anything about this issue.
  To fix the issue, make a copy of the affected file in Windows and
  delete the original.

  Attribute of type 0x80 is the data attribute, which tells where the
  file's data is stored. Apparently Windows allocates space for sparse
  files in multiples of 64 KB (0x10000), and ntfs-3g does not. The
  message from disk scanning in Windows fails to tell you what file is
  involved. I only found the affected file after seeing that sparse
  files use 64 KB chunks, and then searching the file system for sparse
  files.

  I'm attaching a tar file created with the --sparse option. Extracting
  it onto NTFS should create a sparse file which triggers this issue.
  I'm testing with a partition with 4 KB clusters.

  ProblemType: Bug
  DistroRelease: Ubuntu 21.10
  Package: ntfs-3g 1:2017.3.23AR.3-3ubuntu5
  ProcVersionSignature: Ubuntu 5.13.0-25.26-generic 5.13.19
  Uname: Linux 5.13.0-25-generic x86_64
  NonfreeKernelModules: nvidia_modeset nvidia
  ApportVersion: 2.20.11-0ubuntu71
  Architecture: amd64
  CasperMD5CheckResult: unknown
  CurrentDesktop: XFCE
  Date: Mon Jan 17 17:22:47 2022
  SourcePackage: ntfs-3g
  UpgradeStatus: Upgraded to impish on 2021-10-02 (107 days ago)

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