Adam Brenner wrote: > Hello, > > I am trying to understand what a value of -2 means for aLCN. Does anyone > know? > > For example: I see the following when I run ntfscluster: > > ./ntfscluster -f -I 0 /dev/sdc1 > Dump: /$MFT > 0x10 - resident > 0x20 - resident > 0x30 - resident > 0x80 - non-resident > VCN LCN Length > 0 786432 4 > 4 -2 3882300 > 0x80 - non-resident > VCN LCN Length > 0 -2 4 > 4 786436 90684 > 90688 877270 51210 > 141898 1359523 51229 > 193127 1841856 51200 > 244327 2324736 51200 > ... continues ... > > > The NTFS filesystem was created on Windows (Server 2008 R2) and mounted > on linux using ntfs-3g. May someone please explain to this situation to > me? I could not find any documentation that explains this further. > > Quickly looking at the source code, some comments mention that -2 is > mapped to LCN_RL_NOT_MAPPED and the runlist is not yet defined?
The value -2 means just that : it means there is no location defined there for the described range. In your case the mapping list had to be split across two records (because the full list is too big for a single record). In the first record, the location of the first four clusters are defined (cluster 786432 and next three), but the location of the next 3882300 clusters are not defined (at least not defined there), which is indicated by the value -2. In the second record, the location of the first four clusters are not defined (as shown by the value -2), but the location of the next clusters are defined. When you consider both records, all locations are defined exactly once. This is the normal situation. Note 1 : this is the MFT, the entry to the file system which tells where each file, including itself, is located. So for the second record to be accessed, its location must be defined in the first record. As the first record only defines four clusters, one of these four clusters must contain the second record. Note 2 : the LCN_RL_NOT_MAPPED is also used to mark a hole in a sparse file or in a compressed file Regards Jean-Pierre > > Any explanation on this situation and how to properly handle this case > would be very helpful. > > Thanks, > -Adam ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ ntfs-3g-devel mailing list ntfs-3g-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ntfs-3g-devel
