Disable UBIFS compression

Technical Support
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1

Hi, we are using imx7D 512M NAND
It seems that the ubifs defaults to compressing files - i would like to turn that off.
Can this be done by settings in the image.json to make Easy installer create the filesystem uncompressed - or am i on a wrong track ?

any inputs?

Regards Paul

2

Hi, I’m the Toradex AI Assistant. The Toradex Support team will follow up with you shortly!

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Hello Paul,

Thank you for reaching out with your question. To disable UBIFS compression on your iMX7D 512M NAND device, you will need to adjust the UBIFS configuration during the filesystem creation process. Unfortunately, the Toradex Easy Installer’s image.json file does not directly support configuring UBIFS compression settings.

To achieve your goal, you can create a UBIFS image without compression by using the mkfs.ubifs tool with the -x none option. This option ensures that no compression is applied during the creation of the filesystem.

Here’s a simplified approach:

  1. Create a UBIFS Image Without Compression:

    • Use the mkfs.ubifs tool with the -x none option to generate your UBIFS image.

  2. Modify the Installation Process:

    • Ensure that the Toradex Easy Installer uses your custom UBIFS image. This may involve adjusting installation scripts or the image.json file to reference your pre-created UBIFS image.

  3. Test the Configuration:

    • After implementing these changes, test the installation to confirm that the filesystem is installed without compression.

If you are new to creating UBIFS images manually, you might need to explore additional resources or documentation specific to UBIFS and the mkfs.ubifs tool. This process is somewhat beyond the typical configuration capabilities of the Toradex Easy Installer, which focuses more on partitioning and file placement.

I hope this helps! If you have any more questions, feel free to ask.

Best regards,
Toradex AI Assistant

Please, also check if these links can help you solve your problem:

Kernel panic imx7d 1.2.

3

Hello @BDSKPEF,

UBIFS compression is expected to be enabled by default.
Which BSP version are you using?
The output of tdx-info should contain all the relevant information.

Best Regards,
Bruno

Edit: Corrected that UBIFS is expected to have compression enabled by default.

4

I followed the Yocto build instrucrions only set the MACHINE to imx7 and afterwards used Easy Installer (1.8)

making a 4G (zero filled) file on 512M:
df → ubi0:rootfs 431.2M 78.9M 352.3M 18%
dd if=/dev/zero of=big.img bs=4k count=1048576
df → ubi0:rootfs 431.2M 247.9M 183.3M 57% /

tdx-info

Software summary

Bootloader: U-Boot
Kernel version: 6.6.69-7.1.0-devel-00039-g60e3c5841c26 #1 SMP PREEMPT Thu Jan 2 09:32:11 UTC 2025
Kernel command line: ubi.mtd=ubi root=ubi0:rootfs rootfstype=ubifs ubi.fm_autoconvert=1 console=tty1 console=ttymxc0,115200n8 mtdparts=gpmi-nand:512k(mx7-bcb),1536k(u-boot1)ro,1536k(u-boot2)ro,512k(u-boot-env),-(ubi)
Distro name: NAME=“TDX Wayland with XWayland Upstream”
Distro version: VERSION_ID=7.1.0-devel-20250210062823-build.0
Distro variant: -
Hostname: colibri-imx7-14720234

Hardware info

HW model: Toradex Colibri iMX7D on Colibri Evaluation Board V3
Toradex version: 0033 V1.1D
Serial number: 14720234
Processor arch: armv7l

5

Hello @pfarre,

Sorry for the confusion.
UBIFS is indeed using compression by default, I have corrected my original post to reflect that.

The Toradex Easy Installer creates the UBI partitions with mostly default arguments, which include compression for UBIFS.

Avoiding this would require you to use a different method of flashing your device which is not Toradex Easy Installer.
Is the compression having significant overhead in your use case?

Best Regards,
Bruno

6

OK,

i tried the “mkfs_options” in the json - but as the documentation states its only for ext#

The overhead is noticeable, but we will try to run our test system to see the actual impact.