Questions tagged [overlayfs]
For questions concerning the Overlay Filesystem, which was included in Linux kernel 3.18.
130 questions
1 vote
0 answers
39 views
Trying to get ClamAV clamonacc on Linux VM host monitoring the Docker overlay2 file system on the host
I've been trying to get ClamAV's clamonacc on-access scanner to monitor the overlay2 file system where Docker container file systems are mounted on my Linux (Ubuntu 24.04) VM, so that I can detect any ...
- 11
1 vote
0 answers
24 views
Why my attempt to create checkpoint based on hibernate failed?
My idea to create checkpoint based on hibernate is as follow: First I setup my PC to have overlayfs on root file system. It is working correctly. My root partition is /dev/nvme0n1p2, it is mounted ...
- 11
1 vote
1 answer
111 views
How is an overlayfs different from just mounting another disk/partition over a directory?
I have OpenWRT installed on some of my routers and to add additional storage for settings as well as programs that might be installed on the router and maybe logs, OpenWRT recommends you plug storage ...
- 4,971
1 vote
1 answer
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What security risks arise from granting unprivileged users the ability to perform overlay mounts?
I'm writing a program to allow unprivileged users to mount overlay filesystems using a setuid binary. I've implemented a few safeguards to improve the program's security, but I'd like a more ...
- 15
1 vote
1 answer
80 views
SquashFS corruption mechanisms
My embedded Linux system, which uses a SquashFS as its root filesystem, has unexpectedly stopped booting. The system is designed with an OverlayFS mounted on a temporary RAM disk to provide read-write ...
- 61
1 vote
1 answer
89 views
How to merge two directories with failover?
Lets say I have two devices: /dev/sda1 mounted to / (system partition) /dev/sdb1 mounted to /media/data (data partition, usb device may be unplugged) I want to merge/overlay/raid two directories ...
- 550
0 votes
1 answer
291 views
Why does OverlayFS allow unmounting the device that contains upperdir and workdir?
I have two hard drives, each with a single partition (/dev/sda1 and /dev/sdb1). The Linux root is on /dev/sda1. I run the following script. mount /dev/sdb1 /mnt mkdir /data /mnt/upper /mnt/work mount ...
1 vote
1 answer
795 views
Using and debugging `overlayroot` in Ubuntu 24.04 EC2
I'm trying to use the overlayroot package in ubuntu 24.04 to boot into a read only root filesystem but have a writable overlay. Everything I see online says to update the /etc/overlayroot.conf file ...
- 9,379
1 vote
0 answers
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Selective rw access on read-only mounted partition
I have read-only root file system, protected with dm-verity and clean read-write user data storage. Nevertheless, I need to make a tiny set of files on rootfs which require persistent storage ...
- 257
1 vote
2 answers
160 views
Two files with different contents in the linux overlay file system have the same inode
I'm learning about the linux overlay file system and I'm having a problem that's beyond my knowledge. Can anyone explain the technical rationale behind this? mkdir ./{merged,work,upper,lower} echo &...
- 11
1 vote
0 answers
313 views
OverlayFS for User writing changes to root-owned directory
I am trying to give all Users on a system their own writable copy of a root-owned directory, and OverlayFS sounds like the tool for the job, but I am finding it not as straightforward as it sounded at ...
- 5,687
1 vote
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Remounting an overlayfs on underlying filesystem failure
I have quite a bit complex setup. I'm running https://github.com/demostanis/demolinux. The root filesystem is made out of an overlayfs between a btrfs read-only subvolume and a read-write btrfs ...
- 11
0 votes
0 answers
96 views
Load image to docker without dockerd
I want to load docker image without dockerd. (like docker load -i image.tar ) I see that when I load docker image there are files that added to only 2 directories: overlay2,image How can I set the ...
- 25
3 votes
0 answers
466 views
Mounting overlayfs in a user namespace with child mounts
I am trying to mount an overlayfs on /tmp from within a separate user & mount namespace. This works well unless /tmp already has a child mount in the original namespace, in which case this ...
0 votes
1 answer
126 views
Separate default configurations and my own changes with a layered FS : /Data/etc/ upper layer in RO and /etc/ lower layer in RW?
I wish to separate the default packages configuration files (/etc/), and the configuration files I edited e.g. in /Data/etc/ (normally should be /usr/local/etc/, but let assume /Data/etc/). This to ...
