Persistent /var

carbolymer · February 6, 2022, 12:55am

I have configured usb external storage using extroot, and I'd like to have persistent /var directory. I've tried adding entry to /etc/config/fstab and replacing symlink with regular directory but this results in my router being softbricked.

How can I replace /var with regular directory or a mount?

slh · February 6, 2022, 1:01am

That is a build-time decision:

github.com/openwrt/openwrt

base-files: add option to make /var persistent

committed 01:05PM - 25 Feb 19 UTC

stintel

+13 -0

In OpenWrt, /var is symlinked to /tmp by default. This is done to reduce the amo…unt of writes to the flash chip, which often have not the greatest durability. As a result, things like DHCP or UPnP lease files, are not persistent across reboots. Since OpenWrt can run on devices with more durable storage, it makes sense to have an option for a persistent /var. Add an option to make /var persistent. When enabled, /var will no longer be symlinked to /tmp, but /var/run will be symlink to /tmp/run, as it should contains only files that should not be kept during reboot. The option is off by default, to maintain the current behaviour. Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

pmisch · November 20, 2023, 9:02pm

I build an x86 image with TARGET_ROOTFS_PERSIST_VAR set to y but still the /var partition is reset every reboot.
I'm running an pc-engines apu4d4 with a USB flash drive.
Could someone please point me into the right direction.

sn0wbl1nd · August 31, 2024, 4:15am

Are you building using the image builder? I may be having the same problem. When building the image directly /var is a directory, but with the image builder it is always a symbolic link.

pmisch · September 16, 2024, 8:35pm

I gave up on trying, it seemed to cumbersome to handle this.
Someone somewhere once pointed out that this might be fixable by just defining where the runtime like podman or docker stores its data and putting this path onto a bigger + persistant + writeable storage.