$BadClus:$Bad:$DATA anomaly

[gemisigo]

After the last analysis of my volume v: I noticed the following entries in the logfile:

Volume mountpoint:          V:
Volume name:                \\?\Volume{6a2730b8-3ab7-11de-9e03-806e6f6e6963}
Volume type:                NTFS
Total disk space:              67 108 859 904 bytes
                                      62.5000 gigabytes
Bytes per cluster:                      4 096 bytes
.
.
.
The 25 largest items on disk:
Fragments   Bytes          Clusters     Name
------- ----------------- ------- -----
      0    67 108 859 904 16 383 999  V:$BadClus:$Bad:$DATA
      1    10 737 459 712 2 621 451  V:VirtualBox\Disks\XP_DEV_SYS5.dvi
      2    10 737 459 712 2 621 451  V:VirtualBox\Disks\XP_DEV_SYS6.vdi
      1     2 684 365 312 655 363  V:VirtualBox\Disks\XPHunTest_SYS.vdi
      1     2 147 492 352 524 291  V:VirtualBox\Disks\XP_DEV_DB2.vdi
      1     2 147 492 352 524 291  V:VirtualBox\Disks\XP_DEV_DEV2.vdi
      2     1 673 538 048 408 579  V:VirtualBox\Machines\XPHun TestMachine\Snapshots\{8638cfb5-03fc-4cd4-9c56-2b763e5e109c}.vdi
      1       986 720 768 240 899  V:VirtualBox\Machines\XPHun TestMachine\Snapshots\{b0655738-637d-4aef-8412-77217d0402e4}.vdi
      1       256 911 872  62 723  V:VirtualBox\Machines\XPHun TestMachine\Snapshots\{a1f80326-d11a-4deb-8f5e-14afff11ec53}.vdi
      7       222 339 584  54 283  V:VirtualBox\Machines\W2K3D1\Snapshots\{149f4089-8086-46a2-91d8-f6763f60eb85}.vdi
      1        79 702 528  19 459  V:VirtualBox\Machines\XPHun TestMachine\Snapshots\{d793148a-1407-4c32-af0f-17304d0124b4}.vdi
      1        68 928 873  16 829  V:VirtualBox\Machines\XPHun TestMachine\Snapshots\{0ab886f8-ebb0-4945-ae68-1ff6eddbb6e8}.sav
      1        67 108 864  16 384  V:$LogFile
      6        27 508 736   6 712  V:$MFT
      1        18 763 264   4 551  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP6\A0003272.msi
      1        32 665 600   3 448  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP7\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1        31 612 928   3 361  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP6\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1        30 388 224   3 189  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP5\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1        10 485 760   2 560  V:$Extend\$RmMetadata\$TxfLog\$TxfLogContainer00000000000000000001
      1        10 485 760   2 560  V:$Extend\$RmMetadata\$TxfLog\$TxfLogContainer00000000000000000002
      1        19 742 720   2 144  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP4\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1        19 017 728   2 075  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP3\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1        19 017 728   2 075  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP2\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1        19 009 536   2 074  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP1\snapshot\_REGISTRY_MACHINE_SOFTWARE
      1         9 462 256   1 676  V:System Volume Information\_restore{797ACF3E-753C-421A-9239-741219B1AED4}\RP4\A0001145.dll

------- ----------------- ------- -----
     37    99 166 540 121 24 186 427  Total

This is very disturbing since it indicates that the disk contains bad clusters while it does not. Moreover it says that all the disk space is allocated to that "file" even if it is marked to be 0 fragments (nonexisting?) Not to mention the total which counts approximately 1.5x of the real total bytes.

Where does MyDefrag get that data from?

[jeroen]

The $BadClus:$Bad:$DATA file maps the entire disk, it has the exact same size as the disk. It's a sparse file, it does not actually occupy any space (only if there are bad clusters). In the next version I will change the program so it will hide this file from the list of largest items.

[gemisigo]

That's okay, but why is this sparse file not present on other volumes then? What made it suddenly appear out of the blue? It was not there before and the only way to make it vanish was to format that volume.

It is a worrying thing to see and it is inconvenient to format a volume each and every time it shows up Not to mention if it occurs to system partition 

[jeroen]

There have been some changes in MyDefrag... don't worry, just ignore it.