Help Center/ Dedicated Distributed Storage Service/ Getting Started/ Step 4: Initialize a Data Disk/ Introduction to Data Disk Initialization Scenarios and Partition Styles
Updated on 2022-02-21 GMT+08:00
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Introduction to Data Disk Initialization Scenarios and Partition Styles

Scenarios

After a disk is attached to a server, you need to log in to the server to initialize the disk, that is, format the disk. You must initialize a disk before accessing it.
  • System disk

    A system disk does not require manual initialization because it is automatically created and initialized upon server creation. The default disk partition style is master boot record (MBR).

  • Data disk
    • If a data disk is created along with a server, it will be automatically attached to the server.
    • If a data disk is created separately, you need to manually attach it to a server.

    In both cases, you must initialize the data disk before using it. Choose a proper disk partition style based on your service plan.

Constraints

Disks created from backups, snapshots, or images do not need to be initialized. Otherwise, data on the disks may be lost.

Disk Partition Styles

Table 1 lists the common disk partition styles. In Linux, different disk partition styles require different partitioning tools.

Table 1 Disk partition styles

Disk Partition Style

Maximum Disk Capacity Supported

Maximum Number of Partitions Supported

Linux Partitioning Tool

Master Boot Record (MBR)

2 TB
  • 4 primary partitions
  • 3 primary partitions and 1 extended partition
With MBR, one may create several primary partitions and an extended partition. An extended partition must be divided into several logical partitions before use. For example, if 6 partitions need to be created, you can create the partitions in the following two ways:
  • 3 primary partitions and 1 extended partition, with the extended partition divided into 3 logical partitions
  • 1 primary partition and 1 extended partition, with the extended partition divided into 5 logical partitions
  • fdisk
  • parted

Guid Partition Table (GPT)

18 EB

1 EB = 1048576 TB

Unlimited

Disk partitions created using GPT are not categorized.

parted

The maximum disk capacity supported by MBR is 2 TB, and that supported by GPT is 18 EB. Because a data disk currently supports up to 32 TB, use the GPT partition style if your disk capacity is larger than 2 TB.

If you change the disk partition style after the disk has been used, the data on the disk will be cleared. Therefore, select a proper disk partition style when initializing the disk.

Partitioning Operation Guide

For a disk smaller than 2 TB, see the following topics:
For a disk larger than 2 TB, see the following topics: