website: Add description for sparse file

userspace/ksud/src/module.rs

@@ -339,7 +339,7 @@ fn _install_module(zip: &str) -> Result<()> {
         humansize::format_size(zip_uncompressed_size, humansize::DECIMAL)
     );
 
-    let sparse_image_size = 256 * (1 << 30); // 256G
+    let sparse_image_size = 1024 * (1 << 30); // 1T
     if !modules_img_exist && !modules_update_img_exist {
         // if no modules and modules_update, it is brand new installation, we should create a new img
         // create a tmp module img and mount it to modules_update

website/docs/guide/faq.md

@@ -66,3 +66,9 @@ We do not recommend you to modify the system partition directly. You should use
 ## Can KernelSU modify hosts? How can i use AdAway？
 
 Of course. But KernelSU doesn't have builtin hosts support, you can install [systemless-hosts](https://github.com/symbuzzer/systemless-hosts-KernelSU-module) to do it.
+
+## Why is there a huge 1T file?
+
+The 1T size `modules.img` is a disk image file, **don't worry about its size**, it's a special type of file known as a [sparse file](https://en.wikipedia.org/wiki/Sparse_file), its actual size is only the size of the module you use, and it will dynamically shrink after you delete the module; it does not actually occupy 1T of disk space (actually your mobile phone may not have that much space) .
+
+If you're really unhappy with the size of this file, you can use the `resize2fs -M` command to make it the actual size; but the module may not work properly at this time, and we won't provide any support for this.

website/docs/zh_CN/guide/faq.md

@@ -66,3 +66,9 @@ GKI1 跟 GKI2 完全是两个东西，所以你需要自行编译内核。
 ## KernelSU 能修改 hosts 吗，我如何使用 AdAway？
 
 当然可以。但这个功能 KernelSU 没有内置，你可以安装这个 [systemless-hosts](https://github.com/symbuzzer/systemless-hosts-KernelSU-module)
+
+## 为什么有个 1T 的超大文件？
+
+1T 大小的 `modules.img` 是一个磁盘镜像文件，**不要担心它的大小**，它是一种被称之为[稀疏文件](https://en.wikipedia.org/wiki/Sparse_file)的文件格式，它的实际大小只有你使用的模块的大小，并且你在删除模块后它会动态缩小；它并不实际占用 1T 大小的磁盘空间（实际上你手机可能并没有这么多空间）。
+
+如果你真的对这个文件的大小感到不爽，你可以使用 `resize2fs -M` 命令让它变成实际大小；但此时模块可能无法正常工作，我们也不会为此提供任何支持。