问题：文件夹 /etc/security/cacerts 只读权限
beyond1q:/ # cp /data/misc/user/0/cacerts-added/9a5ba575.0 /etc/security/cacerts/
cp: /etc/security/cacerts//9a5ba575.0: Read-only file system
## 实体机，/dev/root 挂载在 /，所以以读写权限重新挂载
HWDUK:/ # echo admin > /etc/security/cacerts/test /system/bin/sh: can't create /etc/security/cacerts/test: Read-only file system 1|HWDUK:/ # cat /proc/mounts | grep "/ " /dev/root / ext4 ro,seclabel,relatime,data=ordered 0 0 HWDUK:/ # mount -o remount,rw / HWDUK:/ # echo admin > /etc/security/cacerts/test HWDUK:/ # cat /etc/security/cacerts/test admin
## 模拟器，/dev/block/sda6 挂载在 /system
beyond1q:/ # echo test > /etc/security/cacerts/test /system/bin/sh: can't create /etc/security/cacerts/test: Read-only file system beyond1q:/ # cat /proc/mounts | grep "/system " /dev/block/sda6 /system ext4 rw,seclabel,noatime 0 0 1|beyond1q:/ # mount -o remount,rw /system beyond1q:/ # echo test > /etc/security/cacerts/test beyond1q:/ # cat /etc/security/cacerts/test test
