Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [overlayfs]

For questions concerning the Overlay Filesystem, which was included in Linux kernel 3.18.

117 questions
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Linux Filesystem Overlay - what is workdir used for? (OverlayFS)

OverlayFS has a workdir option, beside two other directories lowerdir and upperdir, which needs to be an empty directory. Unfortunately the kernel documentation of overlayfs does not talk much about the purpose of this option. The "workdir" needs…
try-catch-finally
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Unionfs vs Aufs vs Overlayfs vs mhddfs, which one do I use

I have randomly been reading about union file system which enables a user to mount multiple filesystems on top of one another simultaneously. However, am finding trouble deciding on which one to use(Unionfs vs Aufs vs Overlayfs vs mhddfs) and why…
David Okwii
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Merge changes to upper filesystem to lower filesystem in Linux Overlay (OverlayFS) mount

I would like to be able to merge changes from the upper filesystem of an overlay mount to a lower filesystem. I am interested both online (i.e. merge while the overlay is mounted) and offline (unmount the overlay and then merge) solutions. I have…
ejm
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How to use OverlayFS to protect the root filesystem?

How do I correctly use OverlayFS to protect my root filesystem? I have an embedded system that boots and runs from an SD card. Since it will experience sudden power loss, I want to protect the root file system. OverlayFS seems like the easiest…
proximous
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12
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How to modify a lower file through an OverlayFS directory?

I want Linux's OverlayFS to behave like AUFS when writing to a lower file. I want it to write through to the lower directory. For example, suppose I have two files named L/lower and U/upper. mount -t overlay -o lowerdir=L,upperdir=U,workdir=W…
Michael Allan
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Querying an overlayfs

I'm looking for a way to query a mounted overlay filesystem (overlayfs) in order to check it's upper and lower directory, but until now I haven't found any suitable command for that. Is there is a way to do such a check ? I mounted the overlayfs…
enzo1959
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Remaining disk space on docker overlay filesystem

I'm new to linux. I installed armbian to an sd card and everything works fine. The sd card is 64GB. Then I installed docker.io, docker-compose and portainer, nothing else. When I check for disk space with lsblk: # lsblk NAME MAJ:MIN RM …
Jimmy
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4 answers

Mount /var/logs as tmpfs, with help of overlayfs to save changes sometimes

Instead of just mounting tmpfs on /var/log I want to use overlayfs. /var/log are writable tmpfs, but containing files were there before tmpfs mount. This old files are not in memory of tmpfs but in lower layer. only changes are stored in tmpfs,…
LeonidMew
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Stackable file system that works like a cache

I am looking for a stackable file system (Like UnionFS, aufs, and OverlayFS) that works similar to bcache or lvmcache but on file level - not on block level: Reads will be done from top-layer. If the file is not there, read the file from…
Ole Tange
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How to mount overlayfs where lower has child mounts?

I'm trying to setup an overlayfs for a chroot environment. The environment is made up from multiple read-only squashfs file systems (lower) and a single writable directory (upper). The tricky part is that only one of the squashfs file systems has…
Philip Couling
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Mounting Overlayfs in a user namespace

Is it possible to mount an Overlayfs filesystem as an unprivileged user in a user namespace in Linux kernels >4.3.3; it seems that the fix to this vulnerability has blocked this functionality entirely. When I create a new user namespace with…
Josh Hebert
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OverlayFS - How to make changes to upper filesystem persistent without unmounting?

I am using an USB drive to start a linux system which needs changes from time to time and also writes some logs. Flash drives tend to fail early if there are many write operations. That brought me to an OverlayFS idea: I want to have a lower…
mgabriel
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Using bind mounts with Overlayfs

I am attempting to create a virtual mount using bind mounts in combination with OverlayFS. What would be most optimal is as follows: The root folder is bind-mounted to a new sub-folder, and used as the lower directory. A new upper directory is…
Zeitwechsler
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Mount root as overlayfs

I've been trying mount root (/) as overlayfs. OS is booting over NFS to RAM. I've added a premount script in initrd, which creates the 'work', 'upper' and 'lower' directories. During the boot process I'm copying the contents of NFS to the 'lower'…
Yurij Goncharuk
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OverlayFS Seamlessly Edit File in Lower Directory

I'm trying to set up a PXEboot environment in which the base system (served over NFS to the PXE clients) is read only, and the root filesystem is an overlayfs filesystem with the read-only NFS base system as the lowerdir and a tmpfs as the…
Travis DePrato
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