Frequently Asked Questions

Q: Why will the hard disk only partition into 4 partitions?

A:

Windows NT only allows you to create up to 4 partitions per logical drive. The technical reason for this is simple. The partition table of every logical drive has 64 bytes reserved specifically for partitioning the drive. Since each partition takes 16 bytes we use the following formula:

64 / 16 = 4

4 = Number of partitions available
16 = Number of bytes needed to store partition information for Each Individual partition
64 = Number of bytes needed to store partition information for Every partition

Usually, this limitation is not an issue unless you have a lot of hard drive space. For example, a server is setup with (6) 9GB hard drives configured as RAID 5. There is another server that has one logical drive setup in this array. This totals out to 45GB of useable storage space.

(6 x 9GB) - 9GB = 45GB One Physical drive is lost to redundancy.

During Windows NT setup, a 1GB partition is made to install Windows NT. The first partition is created and 44GB of hard drive space are left. After installing Windows NT, a decision is made to divide the remaining 44GB of drive space into 4 partitions consisting of 11GB a piece. This process is done in Disk Administrator to partition the remaining 44GB of the logical drive. Only (3) 11GB partitions are allowed, and the remaining 11GB is left as wasted, or unused space. The 4 partition limit has been reached in this example. One primary partition of 1GB and three extended partitions of 11GB each has been created. This creates quite an ordeal since 11GB of drive space are lost.

This limitation cannot be overcome. To avoid this problem some planning must be done before creating the necessary logical drives and installing Windows NT. If more than four partitions per logical drive are going to be created, then it becomes necessary to define additional logical drives in the array of the ADAC BIOS. Still, only 4 partitions per logical drive will be able to be created, but now there are additional drives to partition so this will prevent wasted drive space.

However, it is much easier to manage one logical drive per array in the ADAC BIOS and Then partitioning the drive in Windows NT as opposed to creating multiple logical drives in the array of the ADAC BIOS and then partitioning the with NT. When creating multiple logical drives in the array of the ADAC BIOS and then partitioning them with NT, you are actually creating logical drives within logical drives which can be very confusing.