# Customize

Source: [https://docs.qualcomm.com/doc/80-70014-6/topic/customize.html](https://docs.qualcomm.com/doc/80-70014-6/topic/customize.html)

This section explains how to customize the storage features including adding a new
        partition and mounting the SD card to a specific path.

## File system

ext4 is an open-source file system that is used on data partitions on the Qualcomm
                Linux platform.

ext4 is a [journaling file system](https://en.wikipedia.org/wiki/Journaling_file_system) for Linux. The ext4
                file system can support volumes with sizes in theory up to 64ZB and single files
                with sizes up to 16TB with the standard 4KB block size.

An extent is a range of contiguous physical blocks, improving large-file performance
                and reducing fragmentation. A single extent in ext4 can map up to 128 MiB of contiguous space with a 4 KB block size.

ext4 does not limit the number of subdirectories in a single directory, except by the
                inherent size limit of the directory itself.

For more information, see [An introduction to Linux's EXT4 filesystem |
                    Opensource.com](https://opensource.com/article/17/5/introduction-ext4-filesystem)

Data partition is mounted at /mnt/overlay.

For example:

    /dev/sda9 on /mnt/overlay type ext4 (rw,relatime,rootcontext=system_u:object_r:etc_t:s0,seclabel,stripe=128,inlinecrypt)Copy to clipboard

To mount /dev/sda9 to /data use the
                following commands:

    / # mkdir /home/root/data
    / # mount -o rw,remount /
    / # mount -t ext4 /dev/sda9 /home/root/data
    Copy to clipboard

Note: If you encounter any issues related to SELINUX, please use the following
                    command.

    mount -o rootcontext=system_u:object_r:etc_t:s0 -t ext4 /dev/sda9 /home/root/dataCopy to clipboard

Execute
                    the `mount` command to retrieve the exact
                        `rootcontext=<>` value related to the
                        /mnt/overlay.

## Mount the SD card to a specific path

If the SD card is not mounting automatically, please use the following commands to
                manually remount it to a specific path.

1. Remount the root partition as
                    read-write:

        sh-5.1# mount -o rw,remount /Copy to clipboard
2. Create an SD card directory:

        sh-5.1# mkdir sdcardCopy to clipboard
3. Mount the SD card to the previously created path
                    (*/sdcard*):

        sh-5.1# mount -t vfat /dev/mmcblk1p1 /sdcardCopy to clipboard
4. To verify whether the SD card is mounted, check the available space
                    using:

        sh-5.1# df -h
        ..
        /dev/mmcblk1p1 7.4G 101M 7.4G 2% /sdcardCopy to clipboard

Note: If the SD card has multiple partitions, follow step 3 to
                mount each partition.

## Preferred Vendor List (PVL) memory part information

All UFS parts supported on the Qualcomm SoC are qualified in the PVL validation.
                Select the applicable part from the [Memory list](https://www.qualcomm.com/products/internet-of-things/industrial/building-enterprise/qcs6490/peripherals).

Last Published: Jul 10, 2024

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