====== borg backup ======

Important help:
  * [[https://www.borgbackup.org/releases/borg-2.0.html|Borg 2.0 (preliminary information)]]
  * [[https://borgbackup.readthedocs.io/en/master/usage/general.html#environment-variables|Environment Variables]]
  * [[https://borgbackup.readthedocs.io/en/master/quickstart.html#automating-backups|Automating backups]]

Important info:
  * [[https://borgbackup.readthedocs.io/en/stable/faq.html#can-i-safely-change-the-compression-level-or-algorithm|Can I safely change the compression level or algorithm?]]
  
<code bash>
apt install borgbackup2
</code>

Benchmark compression algos:

<code bash>
borg2 benchmark cpu

Compression ====================================================
lz4          0.1GB      0.048s
zstd,1       0.1GB      0.089s
zstd,3       0.1GB      0.134s
zstd,5       0.1GB      0.180s
zstd,10      0.1GB      0.272s
zstd,16      0.1GB      23.341s
</code>

Benchmark SSH ciphers:
<code bash>
for i in $(ssh -Q ciphers | while read row; do printf "$row "; done); do dd if=/dev/zero bs=1000000 count=1000 2> /dev/null | ssh -c $i localhost "(time -p cat) > /dev/null" 2>&1 | grep real | awk '{print "'$i': "1000 / $2" MB/s" }'; done

aes128-ctr: 317.46 MB/s
aes192-ctr: 216.45 MB/s
aes256-ctr: 298.507 MB/s
aes128-gcm@openssh.com: 269.542 MB/s
aes256-gcm@openssh.com: 256.41 MB/s
chacha20-poly1305@openssh.com: 162.602 MB/s
</code>


<file bash backup.sh>

# create 1G file at remote repository to reserve 
# storage space now for emergencies like 'disk full'

borg repo-space --reserve 1G
</file>