NTFS limitations

The following are a few limitations of NTFS:

Reserved File Names

Though the file system supports paths up to about 32767 Unicode characters with each path component (directory or filename) up to 255 characters long, certain names are unusable, since NTFS stores its metadata in regular (albeit hidden and for the most part inaccessible) files; accordingly, user files cannot use these names. These files are all in the root directory of a volume (and are reserved only for that directory). The names are: $MFT, $MFTMirr, $LogFile, $Volume, $AttrDef, . (dot), $Bitmap, $Boot, $BadClus, $Secure, $Upcase, and $Extend; . (dot) and $Extend are both directories; the others are files.

Maximum Volume Size

In theory, the maximum NTFS volume size is 264-1 clusters. However, the maximum NTFS volume size as implemented in Windows XP Professional is 232-1 clusters. For example, using 64 KiB clusters, the maximum NTFS volume size is 256 TiB minus 64 KiB. Using the default cluster size of 4 KiB, the maximum NTFS volume size is 16 TiB minus 4 KiB. Because partition tables on master boot record (MBR) disks only support partition sizes up to 2 TiB, dynamic or GPT volumes must be used to create bootable NTFS volumes over 2 TiB.

Maximum File Size

Theoretical: 16 EiB minus 1 KiB (264 − 210 bytes). Implementation: 16 TiB minus 64 KiB (244 − 216 bytes)

Alternate Data Streams

Windows system calls may — or may not — handle alternate data streams. Depending on the operating system, utility and remote file system, a file transfer might silently strip data streams. A safe way of copying or moving files is to use the BackupRead and BackupWrite system calls, which allow programs to enumerate streams, to verify whether each stream should be written to the destination volume and to knowingly skip offending streams.

Maximum path length

An absolute path may be up to 32767 characters[28] long; a relative path is limited to 255 characters.

Date range

NTFS uses the same time reckoning as Windows NT: 64-bit timestamps with a range from January 1, 1601 to May 28 60056 at a resolution of ten million ticks per second.