changing permissions of Read-only file system in linux
i use this command to make a bootable flash disk of linux mint
sudo dd if=~/Desktop/linuxmint.iso of=/dev/sdx oflag=direct bs=1048576
it's work, but now my flash disk is lock and i can't change file on it now this file is on flash disk
dr-xr-xr-x 1 ahmad ahmad 2048 May 13 02:24 boot
dr-xr-xr-x 1 ahmad ahmad 2048 May 13 02:24 casper
dr-xr-xr-x 1 ahmad ahmad 2048 May 13 02:23 dists
dr-xr-xr-x 1 ahmad ahmad 2048 May 13 02:24 EFI
dr-xr-xr-x 1 ahmad ahmad 8192 May 13 02:24 isolinux
-r--r--r-- 1 ahmad ahmad 21495 May 13 02:24 MD5SUMS
dr-xr-xr-x 1 ahmad ahmad 2048 May 13 02:23 pool
dr-xr-xr-x 1 ahmad ahmad 2048 May 13 02:24 preseed
-r--r--r-- 1 ahmad ahmad 220 May 13 02:24 README.diskdefines
i try sudo chmod 777 * on my disk but it don't work
migrated from stackoverflow.com Jul 14 '14 at 8:09
This question came from our site for professional and enthusiast programmers.
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1You can't change permissions on a ISO 9660 filesystem. – Ignacio Vazquez-Abrams Jul 14 '14 at 8:10
However you can write your resulting /dev/sdX device. After you are done with dd as you mentioned you can mount /dev/sdX as RW when you didn't boot you system from this device.
- If you have already mounted this device, and it is Read Only, you can remount it in RW by
sudo mount -o remount,rw /dev/sdX , but it works only if you are not running your / system from this partition. Check the partitions mounted with mount -l. Well, actually running OS from this device you will see that the file system changes that you have done can be seen during the sessionm but it's a kind of illusion, they will no be written to the disk.
- If you need to have a different data set in the iso file, you need it to mount, copy this data, modify and then make a new ISO by something like.
mkisofs -o /tmp/cd.iso /tmp/directory/ To make an ISO from files on your hard drive.
- If you need to make a bootable USB drive from your image: choose either
Startup Disk Creatoror UNetbootin. And if you want to make changes to be saved after you worked in OS on you USB drive you need to tell aboutpersistenceto these programs at the disc creation stage.
in Startup Disk Creator:
in UNetbootin:
You can't change permissions nor alter any data in an ISO 9660 filesystem since it's read-only by nature. Despite this you can opt to somehow update data on it if your record format supports multiple sessions. The only thing to consider is that can't change it the normal way in the UNIX filesystem. You may find this howto helpful. Directly creating a new ISO image than having multiple sessions may also be a better practice. The only thing is that it's complicated when you're creating an isolinux-bootable one.
https://superuser.com/questions/782847/changing-permissions-of-read-only-file-system-in-linux
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错误：chmod: changing permissions of ‘/etc/passwd': Read-only file system
给passwd文件加权限，修改/etc/passwd目录下所有的文件夹属性为可写可读可执行，执行以下命令：chomd 777 /etc/passwd
的时候提示错误：
chmod: changing permissions of ‘/etc/passwd': Read-only file system
解决方法：
产生这个问题的原因是文件系统此时处于只读模式下，/etc/passwd和/etc/shadow不能被修改，运行下面的命令就可以解决这个问题
#mount -rw -o remount /
注：
mount 是挂载命令
-rw 是说指定的挂载文件是可读/写的
-o remount / 是说重新挂载根
