Openwrt-System just look well, But exec `ls` in /, it would bloc('ls' can`t present results)

Hello Guys,
My Route(use MT7621) start well(just look well), But something happened abnormal, The abnormal phenomena are as follows:
1. when i enter / , i can not exec ls successfully(it can`t present results, just block)
2. so i I go into the directories under the root directory one by one, i found can not enter /overlay and /root(just block, other directories can enter normal)
3. my own program also behave abnormal, also just block(about open mysql table)
4.restart the system, it can be back to normal, Seems to happen by accident

So, can someone give some advices, and how to troubleshoot and resolve it?


I put a few screenshots of the scene

exec mount, results below:
rootfs on / type rootfs (rw)
/dev/root on /rom type squashfs (ro,relatime)
proc on /proc type proc (rw,noatime)
sysfs on /sys type sysfs (rw,noatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noatime)
/dev/mtdblock7 on /overlay type jffs2 (rw,noatime)
overlayfs:/overlay on / type overlayfs (rw,noatime,lowerdir=/,upperdir=/overlay)
tmpfs on /dev type tmpfs (rw,relatime,size=512k,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
debugfs on /sys/kernel/debug type debugfs (rw,noatime)
/dev/mtdblock6 on /mnt/mtdblock6 type squashfs (ro,relatime)

root@OpenWrt:~# cd ..
root@OpenWrt:/# ls
bin      etc      mnt      proc     root     sys      usr      www
dev      lib      overlay  rom      sbin     tmp      var

root@OpenWrt:/# cd tmp
root@OpenWrt:/tmp# ls
TZ             etc            log            run            tmp
board.json     hosts          overlay        shm
dhcp.leases    lib            resolv.conf    state
dnsmasq.d      lock           resolv.conf.d  sysinfo

You may be out of RAM. Running mysql server takes a lot of resources.

1 Like

if the problem is out of ram, why restart would be ok? is there some other ideas

what`s this meaning

What does "block" mean?

I assume you get an error?

Can you sow these errors?

Because it stops the RAM.


I thought you were trying to execute ls ?

You must be able to enter /root - it's the directory upon login:

root@OpenWrt:~# pwd
root@OpenWrt:~# cd ~
root@OpenWrt:~# pwd
root@OpenWrt:~# ls

:bulb: BTW, on a freshly installed OpenWrt system, there's no files or folders in /root ! :wink:

What version of OpenWrt are you running?

block means "nothing returns, and the terminal is dead<just dead, cant input anything>" , /root and /overlay just cant exec ls

Stop mysql, run free to show available memory.

Restart MySQL, run free again.

If memory is over 85% consumed add swap on a usb drive.

As above, what ver is this? Running on what device? What are you trying to use it for?

1 Like

Can you do this?

root@OpenWrt:~# cd ..
root@OpenWrt:/# cd overlay
root@OpenWrt:/overlay# ls
upper  work

If not, I would reflash the sysupgrade image of the version you're using, if it's the release.

Otherwise, if it's a snapshot, get the newest.

Backup your configs first.