diff --git a/Software Notes/git/git-commands.txt b/Software Notes/git/git-commands.txt
old mode 100755
new mode 100644
diff --git a/Software Notes/git/git-submodules.txt b/Software Notes/git/git-submodules.txt
old mode 100755
new mode 100644
diff --git a/Software Notes/linux/linux_general.txt b/Software Notes/linux/linux_general.txt
old mode 100755
new mode 100644
diff --git a/Software Notes/linux/linux_users.txt b/Software Notes/linux/linux_users.txt
old mode 100755
new mode 100644
diff --git a/Software Notes/linux/mysql_commands.txt b/Software Notes/linux/mysql_commands.txt
old mode 100755
new mode 100644
diff --git a/Software Notes/linux/postgres_commands.txt b/Software Notes/linux/postgres_commands.txt
old mode 100755
new mode 100644
diff --git a/Software Notes/linux/tar_commands.txt b/Software Notes/linux/tar_commands.txt
new file mode 100644
index 0000000..38056c2
--- /dev/null
+++ b/Software Notes/linux/tar_commands.txt	
@@ -0,0 +1,12 @@
+Compress a folder into .tar.gz
+tar -czvf archive_name.tar.gz folder_name
+
+Extract a folder from .tar.gz
+tar -xzvf archive_name.tar.gz
+
+Multithreaded compression
+tar -I pigz -cvf archive.tar.gz paths_to_archive
+
+Multithreaded decompression
+tar -I pigz -xvf archive.tar.gz
+