System volume 'root' usage is 100%

In addition, I noticed that they were on 6.0 so I went ahead and updated to the latest version. Still getting the error.

It could possibly be a log file. The logs are kept trimmed automatically but if a log file grows very fast this might not happen. To look into this SSH access or tech support mode is required.

What command should I do from ssh? I'll get that set up today.

If you can SSH in you could use the du command.

Thank you for the advice, I will post the results once I've run the command

root@nas-server:~# df -h
Filesystem      Size  Used Avail Use% Mounted on
rootfs          4.0G  3.9G     0 100% /
tmpfs            10M  4.0K   10M   1% /dev
/dev/md0        4.0G  3.9G     0 100% /
tmpfs           248M     0  248M   0% /dev/shm
tmpfs           248M  792K  247M   1% /run
tmpfs           248M     0  248M   0% /sys/fs/cgroup
tmpfs           248M  8.0K  248M   1% /media
/dev/md/data-0  462G  7.5G  436G   2% /data
/dev/md/data-0  462G  7.5G  436G   2% /apps
/dev/md/data-0  462G  7.5G  436G   2% /home
/dev/sdc1       597G  7.0G  590G   2% /media/USB_HDD_2
/dev/md/data-0  462G  7.5G  436G   2% /run/nfs4/home
/dev/sdc1       597G  7.0G  590G   2% /run/nfs4/media/USB_HDD_2

I do very little command line, how do I find out what files/folders are specifically too big?

There are multiple ways of doing it but I would tend to do things like:

# du -csh /var
# du -csh /var/*

Fixed that problem, caused a bigger one. I'll let you see what I did....

root@nas-server:~# du -csh /var
3.6G    /var
3.6G    total
root@nas-server:~# du -csh /var/*
4.0K    /var/agentx
46M     /var/backups
34M     /var/cache
4.0K    /var/cores
4.0K    /var/ftp
38M     /var/lib
4.0K    /var/local
0       /var/lock
3.5G    /var/log
4.0K    /var/mail
12K     /var/netatalk
4.0K    /var/opt
368K    /var/readynasd
0       /var/run
16K     /var/spool
4.0K    /var/tmp
8.0K    /var/www
3.6G    total

So it appears that the log folder was totally full. So instead of being smart and deleting the logs from Frontview (or w/e the web interface is called in OS 6), I decided to try and be smart and delete all the logs from the shell...

root@nas-server:~# rm -rf /var/log/*
root@nas-server:~# du -csh /var/*
4.0K    /var/agentx
46M     /var/backups
11M     /var/cache
4.0K    /var/cores
4.0K    /var/ftp
38M     /var/lib
4.0K    /var/local
0       /var/lock
12K     /var/log
4.0K    /var/mail
12K     /var/netatalk
4.0K    /var/opt
368K    /var/readynasd
0       /var/run
16K     /var/spool
4.0K    /var/tmp
8.0K    /var/www
93M     total

It worked. But, it deleted all the subdirectories in the /var/log folder, which are required by ReadyNAS to write logs period. I went and tried turning on email alerts again and kept getting an error that the log/*whatever* directory didn't exist...

So, can anyone running 6.1.1 give me a list of all the subdirectories of /var/log in a clean install??? I really don't want to do a factory reset for such a minor error...

Ok, the actual error message said that "/var/log/frontview/msmtp.log" didn't exist, so I created that directory and file.

root@nas-server:/var/log# mkdir frontview
root@nas-server:/var/log# cd frontview
root@nas-server:/var/log/frontview# touch msmtp.log

That allowed me to send alert messages now. But I'm worried that I've deleted more folders/files that are gonna cause issues down the road. If I have to do a factory reset, I can, I would just like to avoid it if I can find another solution.

Try

# touch /.os_update
# rn_shutdown -r

The above will get the NAS to do an OS Re-install which will re-install the OS but leave your data intact.

I would have recommended finding the log file(s) that filled the OS partition and overwriting them e.g.

# echo "" > /var/log/mylog.log

 

Clarification: Please note that an OS Re-install should only be done after space on the OS partition has been freed up. Doing an OS Re-install whilst the OS partition is very full may lead to further issues.