On Wed, Mar 12, 2008 at 12:47:02AM +0100, Christian Pernegger wrote: > > Is there a difference between running blockdev --setra and echo-int to > > /sys/block/.../read_ahead_kb for devices that have the entry in /sys? > > To answer myself, blockdev --setra seems to change > /sys/block/.../read_ahead_kb, so I'll just always use that. > > > How is readahead handled when "stacked" virtual block devices are > > involved? > > Ran quite a few tests and readahead at any layer but the top layer did > not have any effect. This means that read ahead blocks will always be > decrypted. Oh well ... > Just to make it clear.. with "top layer" you mean you set read ahead only for the dm-crypt device and NOT for the md-raid and/or physical sdX devices? -- Pasi -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
