Regardless of the file system, Windows NT uses cluster size (allocation unit) when organizing your hard disk. An Allocation unit represents the smallest amount of disk space used for a file. If allocation unit was 8192 bytes, on average each file would waste 4096 bytes. The average amount of wasted space on a partition is (Allocation Unit / 2) * (Number of files).
When formatting a disk, without the /A: (Allocation Unit) switch, the following default Allocation Unit sizes are used (assuming a standard 512 byte physical sector size):
NTFS
On NTFS partitions, a MFT (Master File Table) entry takes 1024 bytes, so using 512 bytes Allocation Units practically guarantees fragmentation of the MFT. Unfortuneatly, CONVERT, uses 512 bytes Allocation Units.
A CONVERT is also used when you install and choose NTFS, unless the partition is preformated as NTFS.
Preformatting with NTFS requires one of the following:
1. Multiple disk drives.
How to install with multiple drives (or partitions).
1. Install a trash copy of Windows NT on drive 1 as FAT. I partition it as ~500MB so I can do the install.
Partition Size (MB)(low)
Partition Size (MB)(high)
Allocation Unit
Sectors
1
512
512 bytes
1
513
1024
1024 bytes
2
1025
2048
2048 bytes
4
2049
2**64
4096 bytes
8
Partition Size (MB)(low)
Partition Size (MB)(high)
Allocation Unit
Sectors
1
15
4KB (FAT-12)
8
16
127
2K
4
128
255
4KB
8
256
511
8KB
16
512
1023
16KB
32
1024
2047
32KB
64
2048
4095
64KB
128
4096
8191
128KB
256
8192
16384
256KB
512
2. Multiple partitions.
3. Another Windows NT system that can mount your drive.
2. Format the 2nd drive.
3. Install a maintenance (emergency) copy of Windows NT on the 2nd drive into NTmaint.
4. From the maintenance install, use Disk Administrator to repartition drive 1 as 1 partition.
5. Format the 1st drive.
6. Install your primary Windows NT on the first drive.
7. Edit C:\boot.ini and add the maintenance install. See tip 055 or tip 286.
8. Create a boot floppy.
