eMMC endurance for /var/log

[m11k]

I haven't been able to find any specs on the eMMC module in the helios64.  I've found some posts online indicating that it is a samsung KLMAG1JETD-B041, but I haven't been able to find any info on the write endurance of this module (not sure if it is standard for eMMC vendors to provide that information like SSD vendors).

 

I have been able to run `mmc extcsd read /dev/mmcblk1`, which shows that the emmc life time estimation is between 0 and 10%, but since this value is in 10% increments, its not very helpful.

 

I've had issues with the default ramlog-based /var/log, so I had to turn it off.  I've increased the size to 250MB but it regularly fills up because the 'sysstat', 'pcp' (for cockpit-pcp), and 'atop' packages all write persistent logs into /var/log, which 'armbian-truncate-logs' doesn't clean up.  I could probably update the armbian-truncate-logs script to support these tools if that was the only issue.  However I've also enabled the systemd persistent journal, and although I can see that armbian-truncate-logs is calling journalctl, I still get messages about corrupt journals.  Also `journalctl` only reads logs from /var/log/journal, not /var/log.hdd/journal, so it is only able to show the current day's logs, which isn't very useful.

 

So I'm trying to determine if I should be safe to have /var/log on disk without the ramlog overlay.  Any recommendations?  I do have my root filesystem on btrfs, and /var/log in a separate subvolume.  Maybe there's some way to tweak how frequently to sync /var/log to disk, but I don't know of any mechanism off the top of my head.

 

Thanks,

Mike