Maximum Volume Sizes

The maximum size of a volume depends on the file system used to format the volume. Windows 2000 allows you to format volumes with three different file systems: NTFS, FAT16, and FAT32.

Windows 2000 has the capability to combine noncontiguous disk areas when creating volume sets and stripe sets, but these volumes have the same maximum size limitations of a single volume.

Maximum Sizes on FAT16 Volumes

FAT16 can support a maximum of 65,535 clusters per volume. Table 3.10 lists FAT16 size limits.

Important

For Windows NT and Windows 2000, the cluster size of FAT16 volumes between 2 GB and 4 GB is 64 KB. This cluster size is known to create compatibility issues with some applications. For this reason, it is recommended that FAT32 be used on volumes that are between 2 GB and 4 GB. One of the known compatibility issues involves setup programs that do not compute volume free space properly on a volume with 64 KB clusters and will not run because of a perceived lack of free space. The Format program in Windows 2000 displays a warning and asks for a confirmation before formatting a volume with 64 KB clusters.

Table 3.10 FAT16 Size Limits

Description	Limit
Maximum file size	232 - 1 bytes
Maximum volume size	4 GB
Files per volume	216

Maximum Sizes on FAT32 Volumes

The FAT32 volume must have at least 65,527 clusters. The maximum number of clusters on a FAT32 volume is 4,177,918. Windows 2000 creates volumes up to 32 GB, but you can use larger volumes created by other operating systems such as Windows 98. Table 3.11 lists FAT32 size limits.

Table 3.11 FAT32 Size Limits

Description	Limit
Maximum file size	232 - 1 bytes
Maximum volume size	32 GB (This is due to the Windows 2000 format utility. The maximum volume size that Windows 98 can create is 127.53 GB).
Files per volume	Approximately 4 million

Important

Windows 2000 can format new FAT32 volumes up to 32 GB in size but can mount larger volumes (for example, up to 127.53 GB and 4,177,918 clusters from a volume formatted with the limits of Windows 98). It is possible to mount volumes that exceed these limits, but doing so has not been tested and is not recommended.

Maximum Sizes on NTFS Volumes

In theory, the maximum NTFS volume size is 2³² clusters. However, even if there were hardware available to supply a logical volume of that capacity, there are other limitations to the maximum size of a volume.

One of these limitations is partition tables. By industry standards, partition tables are limited to 2³² sectors. Sector size, another limitation, is a function of hardware and industry standards, and is typically 512 bytes. While sector sizes might increase in the future, the current size puts a limit on a single volume of 2 terabytes (2³² * 512 bytes, or 2⁴¹ bytes).

For now, 2 terabytes should be considered the practical limit for both physical and logical volumes using NTFS.

The maximum number of files on an NTFS volume is 2³² - 1. Table 3.12 lists NTFS size limits.

Table 3.12 NTFS Size Limits

Description	Limit
Maximum file size	264 bytes - 1 KB (On disk format) 244 bytes - 64 KB (Implementation)
Maximum volume size	264 allocation units (On disk format) 232 allocation units (Implementation)
Files per volume	232 - 1

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