Migrate from ramlog to disk

[wurmfood]

Is there an accepted procedure for moving from using ramlog to logging to disk? I've looked but everything I can find is about setting up ramlog.

 

I assume it's more complicated than just creating a partition (or ZFS dataset) and mounting it /var/log, disabling ramlog, and rebooting.

[Werner]

23 minutes ago, wurmfood said:

mounting it /var/log, disabling ramlog, and rebooting.

Actually that is what I would do at first try.

[wurmfood]

Well, for anyone else interested in trying this, here's the basic order I did:

• stop armbian-ramlog
• disable armbian-ramlog
• create a zfs dataset and mount it at /var/log
• cp -ar everything from /var/log.hdd to the new /var/log
• modify /etc/logrotate to disable compression (since the dataset is already using compression)
• modify /etc/default/armbian-ramlog to disable it there as well
• modify /etc/default/armbian-zram-config to adjust for new numbers (I have ZRAM_PERCENTAGE and MEM_LIMIT_PERCENTAGE at 15).
• reboot

[0x349850341010010101010100]

Hi,

 

I had that same idea and I'm just setting this up based on your suggestions.
Thank you for starting the thread.

Just one thing: There is no option regarding compression in /etc/default/armbian-zram-config, or did you mean to disable another option?

 

[wurmfood]

Sorry, the line about disabling was just to make sure you disable the armbian-zram-config service by setting ENABLED to false.

 

As a warning, though, I found some problems with this if you log to a zfs share. It seems you have to make sure zfs gets loaded before the logging starts up, otherwise you can get a kernel panic on occasion. I didn't really dig into how to fix this, so I just log and swap to a usb drive instead now.

[0x349850341010010101010100]

5 hours ago, wurmfood said:

Sorry, the line about disabling was just to make sure you disable the armbian-zram-config service by setting ENABLED to false.

 

As a warning, though, I found some problems with this if you log to a zfs share. It seems you have to make sure zfs gets loaded before the logging starts up, otherwise you can get a kernel panic on occasion. I didn't really dig into how to fix this, so I just log and swap to a usb drive instead now.

Thank you for clarifying and pointing that out.
Logging to a USB drive as a swap seems like a neat workaround.
It would be better though, if we could work out how to avoid the kernel panics without having to change when zfs mounts.