Log2Zram

Usefull for IoD / maker projects for reducing SD, Nand and Emmc block wear via log operations. Uses Zram to minimise precious memory footprint and extremely infrequent write outs.

Log2Zam is a lower write fork https://github.com/azlux/log2ram based on transient log for Systemd here : A transient /var/log

Can not be used for mission critical logging applications where a system crash and log loss is unaceptable. If the extremely unlikely event of a system crash is not a major concern then L2Z can massively reduce log block wear whilst maintinaing and extremely tiny memory footprint.

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Menu

1. Install
2. Upgrade
3. Customize
4. It is working ?
5. Uninstall

Install

sudo apt-get install git rsync
git clone https://github.com/StuartIanNaylor/log2zram
cd log2zram
sudo sh install.sh

Customize

variables :

In the file /etc/log2ram.conf, there are three variables:

• SIZE: defines the size the log folder will reserve into the RAM (default is 40M).
• USE_RSYNC: Can be set to true if you prefer ´rsync´ rather than ´cp´. I use the command cp -u and rsync -X, I don’t copy the all folder every time for optimization.
• MAIL: Disables the error system mail if there is not enough place on RAM (if set to false)

refresh time:

By default Log2Zram checks available log space every hour. It them makes a comparison of the percentage set via Prune_Level and only writes out old logs to disk when triggered and then removes the collected old logs from zram space.

It is working?

You can now check the mount folder in ram with (You will see lines with log2ram if working)

# df -h
…
log2ram          40M  532K   40M   2% /var/log
…

# mount
…
log2ram on /var/log type tmpfs (rw,nosuid,nodev,noexec,relatime,size=40960k,mode=755)
…

Testing

sudo service log2ram reload

Checks PRUNE_LEVEL < available free space if true will move and clean /var/log/oldlog to hdd.log

sudo logrotate -vf /etc/logrotate.conf

Force the daily logrotate with verbose output

If you have issue with apache2, you can try to add apache2.service next to other services on the Before parameter in /etc/systemd/system/log2ram.service it will solve the pb

The log for log2ram will be written at: /var/log/log2ram.log

Compressor name	Ratio	Compression	Decompress.
zstd 1.3.4 -1	2.877	470 MB/s	1380 MB/s
zlib 1.2.11 -1	2.743	110 MB/s	400 MB/s
brotli 1.0.2 -0	2.701	410 MB/s	430 MB/s
quicklz 1.5.0 -1	2.238	550 MB/s	710 MB/s
lzo1x 2.09 -1	2.108	650 MB/s	830 MB/s
lz4 1.8.1	2.101	750 MB/s	3700 MB/s
snappy 1.1.4	2.091	530 MB/s	1800 MB/s
lzf 3.6 -1	2.077	400 MB/s	860 MB/s

Uninstall :(

chmod +x /usr/local/bin/uninstall-log2ram.sh && sudo /usr/local/bin/uninstall-log2ram.sh

Also /var/oldlog contains the pruned logs from install delete if not required (prob not)