EMMC Mounting

[davidzhou]

Hi,

I have imx6ul dev board and Linux 4.15 yocto.

My emmc drive is mount as /media/emmc.

When I copy files into emmc every time, it also takes some flash memory space from the system because the emmc is mounted to the root file system. Is that TRUE?

This causes an error that file system is full, even there is a lot of space is still available.

My question is how to resolve this problem.

Thank you,

David Zhou

[b36401]

Please note that there are 2 resources that you may lack on the filesystem: blocks and inodes.
I mean if you have many small files then possibly there is free space on the filesystem in point of blocks but no free inodes.
You can check inodes with "df -i".

Have a great day,
Victor

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[davidzhou]

Hi Victor,

The df-i   command shows inodes in the ubi1_0 filesystem all zeros (0 inodes, 0 used, 0 available).

At the beginning, there is 38M available in the ubi1_0. Then I copied a big file from one folder to another in the EMMC. As the result, there is only 8M available in the ubi1_0 ( the file size is 61M).

I am wondering why it takes so much space in the ubi1_0 filesystem while using EMMC flash memory?  It seems it is not just the inodes. It also related to the file size itself. Or something is not right.

Thank you for your help.

David Zhou

[b36401]

It is strange if moving a file from one folder to another reduces free space on filesystem.
Please perform "du" for source and destination folder before and after moving the file.
Possibly the tool you are using to move the file does not remove it from source folder.

[davidzhou]

Hi Victor,

The command is COPY, not MV. 

RECAP:  ubi1_0 file system is 128 M partition. (On-chip flash, 256M totoal)

               EMMC is 8G on-board external flash.

               61M file is copied from one folder to another folder, both are in the EMMC. BUT it also took up 30M space on ubi1_0. 

               emmc is mounted as a ubi1_0 folder.

The df -i command show inodes 0. Is this because inode is not enabled?

Thank You,

David

[davidzhou]

Hi Victor,

Finally, it is resolved. Actually it was my own mistake. For some reason (long time ago), the emmc was not mounted at all. The folder created for the emmc mounting is used as actual folder. That it why it takes so much memory.

Regards,

David