lvmconfig: add page (#18036)

add lvmconfig page

pages/linux/lvmconfig.md

@@ -0,0 +1,28 @@
+# lvmconfig
+
+> Display and manipulate LVM configuration information.
+> More information: <https://manned.org/lvmconfig>.
+
+- Display the effective configuration in use (after merging all config sources):
+
+`lvmconfig --typeconfig current --mergedconfig`
+
+- Show only settings that differ from their defaults:
+
+`lvmconfig --typeconfig diff`
+
+- List all configuration keys:
+
+`lvmconfig {{[-l|--list]}}`
+
+- Print the default configuration with full comments and extra spacing:
+
+`lvmconfig --typeconfig default --withcomments --withspaces`
+
+- Validate the full merged configuration and report errors:
+
+`lvmconfig --mergedconfig --validate`
+
+- Write the current effective configuration to a file:
+
+`lvmconfig --typeconfig current {{[-f|--file]}} {{path/to/output.conf}}`