Differences

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--- software:files [2024/04/13 13:11]
cyril [Creation]
+++ software:files [2024/04/16 12:46]
cyril [Digital Will]
@@ Line 150: / Line 150: @@
 === Borg Backup ===
+  * Create a Borg repository in the current folder: <code>borg init -e <encryption> [--append-only]</code>
+    * ''<encryption>'' can be:
+      * ''none'' to disable it, for instance on an already encrypted volume
+      * ''repokey'' to enable it (or ''repokey-blake2'' to use Blake2 instead of Sha256, which is often faster)
+      * ''authenticated'' to disable encryption but still enable authentication (or ''authenticated-blake2'' to use Blake2)
+    * ''--append-only'' means that no data can be removed with borg, archives can only be added. It can be used to protect an online repository against malware.
+  * Create archives: <code>borg create <repo>::<!archive> <path> --stats --progress
+    --compression auto,zstd,12 --chunker-params 15,23,19,4095 --noatime --noctime -x --exclude-caches</code>
+    * ''--compression'': it can make sense to adjust the compression level depending on your computer speed and your storage speed, so that compression does not slow down the backup, but still save as much space as possible under this constraint. However it is not always easy to find an universal value (data that compress very well are mostly limited by the input storage speed, while data that compress less well are mostly limited by the output storage speed). You have roughly the choice between LZ4 (very quick), LZMA (very high compression ratio), and ZSTD (wide-range) in between.
+    * ''--chunker-params'': this is also an important but a bit complicated tuning. Originally default value was creating small chunks causing huge cache and memory usage, so they switched to much larger chunks, but which can be too large for some applications (for instance when modifying only metadata of an image file, we want to deduplicate the data), so I came with this compromise ''15,23,19,4095''.
+  * ''borg info <repo>''
+  * ''borg list <repo>''
+  * ''borg info <repo>::<archive>''
 === Restic ===
@@ Line 164: / Line 177: @@
+===== Container files =====
+Sources:
+  * [[https://serverfault.com/questions/696554/creating-a-grow-on-demand-encrypted-volume-with-luks|Excellent demonstration]] for creating a growing container file with LUKS and EXT4 using sparse files.
 ===== Digital Will =====