PXB-3357 PXB-3357 Document that xtrabackup --decompress requires the …

…zstd to be installed (8.4) (#319)

modified:   docs/prepare-compressed-backup.md

docs/prepare-compressed-backup.md

@@ -1,20 +1,54 @@
-# Prepare the backup
+# Decompress and prepare a backup
 
-Before you can prepare the backup you’ll need to uncompress all the files.
-Percona XtraBackup has implemented `--decompress` option
-that can be used to decompress the backup.
+Before you can prepare the backup you need to decompress all the files.
 
-```{.bash data-prompt="$"}
-$ xtrabackup --decompress --target-dir=/data/compressed/
-```
+## Decompress a backup
+
+* To decompress backups made using `LZ4` or `ZSTD` compression algorithm, install the corresponding package.
+
+    `Install on APT systems`
+
+    === "Install the `lz4` package"
+
+        ```{.bash data-prompt="$"}
+        $ sudo apt install lz4
+        ```
+
+    === "Install the `zstd` package"
+
+        ```{.bash data-prompt="$"}
+        $ sudo apt install zstd
+        ```
 
-!!! note
+    `Install on YUM systems`
+
+    === "Install the `lz4` package"
+
+        ```{.bash data-prompt="$"}
+        $ sudo yum install lz4
+        ```
+
+    === "Install the `zstd` package"
+
+        ```{.bash data-prompt="$"}
+        $ sudo yum install zstd
+        ```
+
+*  Use the `--decompress` option to decompress the backup.
+
+    ```{.bash data-prompt="$"}
+    $ xtrabackup --decompress --target-dir=/data/compressed/
+    ```
+
+    !!! note
 
-    `--parallel` can be used with `--decompress` option to decompress multiple files simultaneously. 
+        `--parallel` can be used with `--decompress` option to decompress multiple files simultaneously. 
+
+    Percona XtraBackup does not automatically delete compressed files. To clean up the backup directory, use the `--remove-original` option. If you do not remove the compressed files, these files will not be copied or moved to the datadir when using the `--copy-back` or `--move-back` options.
 
-Percona XtraBackup does not automatically remove the compressed files. In order to clean up the backup directory you should use `--remove-original` option. Even if they’re not removed these files will not be copied/moved over to the datadir if `--copy-back` or `--move-back` are used.
+## Prepare the backup
 
-When the files are uncompressed you can prepare the backup with the `--prepare` option:
+When the files are decompressed you can prepare the backup with the `--prepare` option.
 
 ```{.bash data-prompt="$"}
 $ xtrabackup --prepare --target-dir=/data/compressed/