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This article will explain in detail what is the meaning of ASM DG Usable_file_MB and Req_mir_free_MB, the content of the article is of high quality, so the editor will share it with you for reference. I hope you will have some understanding of the relevant knowledge after reading this article.

The value of REQUIRED_MIRROR_FREE_MB represents the space required by ASM to re-satisfy the redundancy defined by the disk group, depending on the redundancy of the disk group and the number of FailGroup failure groups.

If the normalDG,REQUIRED_MIRROR_FREE_MB value of n > 2 failgroup is equal to the size of one failgroup (if the size of the failure group is inconsistent, the largest failure group is the req_mb size)

If there are only two normalDG for failgroup, then the value of REQUIRED_MIRROR_FREE_MB will be equal to the size of one disk instead of the size of one failgroup.

If there are high redundant disk groups with n > 3 failgroup, the value of REQUIRED_MIRROR_FREE_MB is equal to the size of 2 failgroup

If the high redundant disk group has only three failgroup, then the value of REQUIRED_MIRROR_FREE_MB will be the size of two disks.

In normal mode, when the FG group is greater than 2, then when there is a failure, you must ensure that the whole failure group is supported, so it is calculated according to the failure group at this time.

When the FG group is equal to 2, at this time, because the normal mode is 2 data, just press 1 asm_disk to calculate.

Similarly, in high mode, when the FG group is greater than 3, then when there is a fault, we must ensure that there are at least 2 failed groups to make up for and ensure 3 copies of data.

When FG is equal to 3, it is only 2 asm_disk)

The value of USABLE_FILE_MB represents the total space available to store data, and its value depends on the size of the disk group, the redundancy of the disk group, and the value of REQUIRED_MIRROR_FREE_MB. The value of USABLE_FILE_MB is calculated as follows:

(number of Total_MB/FG / redundancy) * number of remaining broken maximum disk groups

For example:

State Type Rebal Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files Name

MOUNTED HIGH N 512 4096 1048576 34312320 13906410 13724928 60494 0 N DATADG/

(34312320amp 5amp 3) * 3 = 6862464

A maximum of 2 of the 5 failed groups can be broken, and the remaining 3 normal FG are high redundancy (3 redundancy).

Safe values can only be stored in 6862464MB under normal circumstances, and the stored data is guaranteed to be 3-point redundancy. If there is a Usable_file_MB, the data cannot be guaranteed to be 3 copies redundant.

Use_mb= (free_mb-req_mb) / 2 | 3 where the denominator of normal mode is 2 and the denominator of high mode is 3

Free_MB/ redundancy to view the remaining space

About what the meaning of ASM DG Usable_file_MB and Req_mir_free_MB are shared here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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