问问大家，IRF设备升级过程中，需要按y或者n或者A，a是代表all的意思，请问具体分别是啥意思

# 配置IRF的主用下次启动软件为flash:/all.ipe。（IRF模式）

<Sysname> boot-loader file slot1#flash:/all.ipe all main

Verifying the file flash:/all.ipe on slot 1......................................Done.

H3C WX5560H images in IPE:

  Boot.bin

  System.bin

This command will set the main startup software images. Continue? [Y/N]:y

Add images to slot 1.

File flash:/Boot.bin already exists on slot 1.

File flash:/System.bin already exists on slot 1.

Overwrite the existing files? [Y/N]:y

Decompressing file Boot.bin to flash:/Boot.bin........................Done.

Decompressing file System.bin to flash:/System.bin........................Done.

The images that have passed all examinations will be used as the main startup software images at the next reboot on slot 1.

File flash:/Boot.bin already exists on slot 2.

Do you want to overwrite the file?

 Y: Overwrite the file.

 N: Not overwrite the file.

 A: From now on, overwrite or not overwrite without prompt.

Please make a choice. [Y/N/A]:a

What type of overwrite operation do you want to perform?

 Y: Overwrite without prompt.

 N: Not overwrite or display prompt.

 Q: Return to the previous step.

Please make a choice. [Y/N/Q]:y

An existing file will be overwritten without prompt if it has the same name as any upgrade file.

Loading......................Done.

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The images that have passed all examinations will be used as the main startup software images at the next reboot on slot 2.

The images that have passed all examinations will be used as the main startup software images at the next reboot on slot 3.

Decompression completed.

Do you want to delete flash:/all.ipe now? [Y/N]:n