Дискриптор віртуального диска має таки вигляд:

В процесі роботи з віртуальним диском може виникнути необхідність редагування параметрів RW та ddb.geometry.cylinders

Алгоритм розрахунку параметра RW наступний:

(Розмір диску в Гб)*1024*1024*1024/512

Алгоритм розрахунку ddb.geometry.cylinders наступний:

• The number of cylinders is determined by multiplying the number of heads (255) and sectors (63), which equals 16065.

• This number is multiplied by 512, which equals 8225280.

• Divide the total size of the virtual disk in bytes by 8225280, per the value above.

• Round this off to the nearest integer to get the ddb.geometry.cylinders value.

  For example:

  5,368,709,120 / (255 * 63 * 512)
  = 5,368,709,120 / 8225280
  = 652.70837223778400248988484282602
  = 652 cylinders

If the size of the disk is less than 1GB:

• Set ddb.geometry.heads to 64.

• Set ddb.geometry.sectors to 32.

• Set ddb.geometry.cylinders to the integer portion of the value obtained when the size of the disk (in bytes) is divided by 1048576.

  Note: This number (1048576) is generated by multiplying head and sector values, and 512, for the block size.

If the size of the flat file is 1GB or more but less than 2GB:

• Set ddb.geometry.heads to 128.

• Set ddb.geometry.sectors to 32.

• Set ddb.geometry.cylinders to the integer portion of the value obtained when the size of the disk (in bytes) is divided by by 2097152.

If the size of the flat file is 2GB or more:

• Set ddb.geometry.heads to 255.

• Set ddb.geometry.sectors to 63.

• Set ddb.geometry.cylinders to the integer portion of the value obtained when the size of the disk (in bytes) is divided by 8225280.