doc: added sudo for hdparm command.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>

diff --git a/doc/config-cluster/file-system-recommendations.rst b/doc/config-cluster/file-system-recommendations.rst
index 82972d7c4fb6bce857c7f188acb897fa10fddc21..93f52d678babf3f3a744fb70c34e7e7e35170de4 100644 (file)
--- a/doc/config-cluster/file-system-recommendations.rst
+++ b/doc/config-cluster/file-system-recommendations.rst
@@ -9,7 +9,7 @@ disk. Newer kernels should work fine.
 
 Use ``hdparm`` to disable write caching on the hard disk::
 
-       hdparm -W 0 /dev/hda 0
+       sudo hdparm -W 0 /dev/hda 0
 
 In production environments, we recommend running OSDs with an operating system
 disk, and a separate disk(s) for data. If you run data and an operating system