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Zaoxu, Li 305c41bb57 EVS 2.0.38 SP1 version 
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
Co-authored-by: Zaoxu, Li <lizaoxu@huawei.com>
Co-committed-by: Zaoxu, Li <lizaoxu@huawei.com>
2022-10-19 22:27:18 +00:00

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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

A disk created from a data source does not need to be initialized. Such a disk contains the data of the data source in the beginning. Initializing the disk may clear the initial data on this disk.

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.