How To Do File System Alignment
"Allocation Unit Size" is also known as cluster size, allocation unit size is the smallest amount of hard disk space that windows uses to hold a file. Generally, smaller allocation unit sizes result in more efficient use of hard disk space. You can specify the allocation unit size when you format a hard disk drive. If you don't specify a size, windows defaults to a size based on the size of the volume. Use format /A: at the command prompt to override the default allocation unit size, where can be 512, 1024, 2048, 4096, 8192, 16K, 32K, and 64K for FAT, FAT32, and NTFS. FAT and FAT32 also support 128K and 256K for sector sizes greater than 512 bytes. You can't use NTFS compression for allocation unit sizes larger than 4096 bytes. To improve the performance of your disk drive subsystem, consider matching the file system Allocation Unit Size to the block size of the application you are using. For example, suppose SQL Server is using a 4KB block size. When you format a f