Log files not being correctly created

Continuing the discussion from Random Hangs of emonPi/emonSD:

Can someone with the newer SD Card running (I’m still on emonSD-17Oct19) check and see if their logs are being saved correctly by Log2Ram?

It might be an issue introduced with the latest Image.

@TrystanLea @glyn.hudson

Last updated a few months ago -
image



Seems OK to me.

@Vster Thanks for checking - please post as code between backticks ( 3 on a line before and 3 on a line after - ``` or the “Preformatted </>” format button) rather than images (especially if it gets large).

@rdavies6 - you might want to check as well.

We use a RAMLOG system so /var/log is mounted in RAM (to reduce SD Card wear).

[email protected]:~ $ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       4.0G  2.6G  1.2G  68% /
devtmpfs        484M     0  484M   0% /dev
tmpfs           488M     0  488M   0% /dev/shm
tmpfs           488M   56M  433M  12% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           488M     0  488M   0% /sys/fs/cgroup
tmpfs           1.0M     0  1.0M   0% /var/lib/php/sessions
tmpfs           1.0M     0  1.0M   0% /var/tmp
tmpfs            30M     0   30M   0% /tmp
/dev/mmcblk0p1  253M   52M  202M  21% /boot
/dev/mmcblk0p3   10G  734M  8.8G   8% /var/opt/emoncms
log2ram          50M  6.6M   44M  14% /var/log
tmpfs            98M     0   98M   0% /run/user/1000

To preserver the logs, the /var/log folder is saved / restored at boot. logrotate rotates files into a separate folder /var/log.old.

It took me a while to remind myself, but log2ram is triggered hourly by cron (/etc/cron.hourly/log2ram). This same cron job triggers logrotate first.

journalctl -n 50 -u log2ram will tell you what is happening with log2ram.

As @rdavies6 says the rotated files are empty, there may be an issue with logrotate. To investigate you need to look at the logrotate.log file.

Here’s mine emonSD-24Jul20:

Filesystem      Size  Used Avail Use% Mounted on
/dev/root       4.1G  2.7G  1.2G  70% /
devtmpfs        431M     0  431M   0% /dev
tmpfs           463M     0  463M   0% /dev/shm
tmpfs           463M   47M  417M  11% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           463M     0  463M   0% /sys/fs/cgroup
tmpfs           1.0M     0  1.0M   0% /var/lib/php/sessions
tmpfs           1.0M     0  1.0M   0% /var/tmp
tmpfs            30M     0   30M   0% /tmp
/dev/mmcblk0p1  253M   54M  199M  22% /boot
/dev/mmcblk0p3  9.9G  1.6G  7.8G  17% /var/opt/emoncms
log2ram          50M  9.4M   41M  19% /var/log
tmpfs            93M     0   93M   0% /run/user/1000
[email protected]:~ $ journalctl -n 50 -u log2ram
-- Logs begin at Tue 2022-07-12 19:52:59 BST, end at Wed 2022-07-13 22:20:42 BST
Jul 13 19:17:03 emonpi log2ram[6000]: logrotate/logrotate.status
Jul 13 19:17:03 emonpi log2ram[6000]: sent 394,770 bytes  received 7,276 bytes  
Jul 13 19:17:03 emonpi log2ram[6000]: total size is 6,620,785  speedup is 16.47
Jul 13 19:17:03 emonpi systemd[1]: Reloaded Log2Ram.
Jul 13 20:17:01 emonpi systemd[1]: Reloading Log2Ram.
Jul 13 20:17:01 emonpi log2ram[7202]: sending incremental file list
Jul 13 20:17:01 emonpi log2ram[7202]: auth.log
Jul 13 20:17:01 emonpi log2ram[7202]: daemon.log
Jul 13 20:17:01 emonpi log2ram[7202]: log2ram.log
Jul 13 20:17:01 emonpi log2ram[7202]: syslog
Jul 13 20:17:01 emonpi log2ram[7202]: emoncms/wificheck.log
Jul 13 20:17:01 emonpi log2ram[7202]: emonhub/emonhub.log
Jul 13 20:17:01 emonpi log2ram[7202]: logrotate/
Jul 13 20:17:01 emonpi log2ram[7202]: logrotate/logrotate.log
Jul 13 20:17:01 emonpi log2ram[7202]: logrotate/logrotate.status
Jul 13 20:17:01 emonpi log2ram[7202]: sent 3,063,920 bytes  received 6,010 bytes
Jul 13 20:17:01 emonpi log2ram[7202]: total size is 9,674,653  speedup is 3.15
Jul 13 20:17:01 emonpi systemd[1]: Reloaded Log2Ram.
Jul 13 21:17:02 emonpi systemd[1]: Reloading Log2Ram.
Jul 13 21:17:02 emonpi log2ram[8417]: sending incremental file list
Jul 13 21:17:02 emonpi log2ram[8417]: ./
Jul 13 21:17:02 emonpi log2ram[8417]: auth.log

There’s about 1.8MB in rotated logs

1 Like

@borpin Sorry my bad.
@TrystanLea yes, everything looks fine on my Pi too, including big(!) compressed files for the emonhub.1.gz in the /var/log.old/emonhub/ folder. Gunziping the emonhub.log.X.gz files has valid emonhub type logging in it.

1 Like

Ha, no bother. It is one of those things that can easily slip through and not be noticed until you need the logs!