Is it possible let chroot jails share directories(read-only) outside the jail?

You can use the new bind mounts support to make identical directory structures available through multiple paths.

mount --bind /usr/bin /path/to/chroot/jail/usr/binmount -o remount,ro /path/to/chroot/jail/usr/bin

For more details, see mount(8).

You can get really clever with mounting on Linux systems these days; for more details, see the Linux kernel source file Documentation/filesystems/sharedsubtree.txt.

linux debian virtualization chroot

try

mount /outside /inside -o bind

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