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.