universal usb installer使用的一个问题

最新推荐文章于 2025-05-16 20:22:00 发布

vagrant2005

最新推荐文章于 2025-05-16 20:22:00 发布

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本文介绍了Ubuntu Live USB安装过程中关于持久化存储的问题，包括什么是持久化、在持久化系统上能做什么和不能做什么、为什么FAT32格式限制了持久化数据容量不超过4GB，以及如何检查和增加持久化数据的大小。此外，还提供了备份和重用持久化数据的方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

补充：ubuntu官方提供了一个用于在u盘中安装可读写的ubuntu系统的程序：Startup Disk Creator 。

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关于persistence的问题：

1）

What is persistence ?

Usually, on a live CD or Live USB, all modifications are discarded when you reboot.

The persistency allow you to keep your preferences and data even after reboot.

The data are stored in a special file called casper-rw (for Ubuntu) and overlay-USBLABEL-UUID (for Fedora). This is a completely transparent process for the user.

In this step, you have to choose the size of the data you will want to keep. Usually, 300MB is enough to install some few software but you can set more.

2）

What can I do and not do on a persistent system ?

You have to keep in mind that a persistent system is a live system on which there is an overlay that is writable.

This means that core files are in read-only mode while other files are in read/write mode.

What you can't do on a persistent system :

updates core files (kernel etc) = no full system updates
install drivers

What you can do on this kind of system is :

install some softwares
do some software updates
create some files/folders
install Linux (from you key) on your PC hard drive

3）

Why can't I have more than 4GB for persistent data with LiLi ?

This is a limitation of FAT32 filesystem. When a drive is formated using FAT32, the biggest file that can be created is 4GB. Persistence is a file so it follows that rule.

4）

To check the data persistence, boot on your key and create a folder on the desktop then reboot. If it's still there, the persistence is working well.

How can I have more than 4GB of persistent data ?

If it's not working try to create the key again and don't forget to set the persistence size in step 3.

Follow the Pendrive Linux's tutorial.

http://www.pendrivelinux.com/create-a-larger-than-4gb-casper-partition/

5）

To check the data persistence, boot on your key and create a folder on the desktop then reboot. If it's still there, the persistence is working well.

If it's not working try to create the key again and don't forget to set the persistence size in step 3.

6）

Can I backup or re-use my persistent data ?

Yes, you can backup or re-use your data. All you have to do is copying the casper-rw file (for ubuntu and variants) or LiveOS/overlay-LABEL-XXXX file (for Fedora) when you are in windows. You can even put this file on another LinuxLive key with the same config to access your data.