Re: Bug#648367: device-mapper devices such as dm-crypt always have rotational=1; should inherit "rotational" setting from underlying devices

["Stefan Lippers-Hollmann" <s.L-H@gmx.de>]

Hi

On Monday 14 November 2011, Josh Triplett wrote:
> Source: linux-2.6
> Version: 3.1.0-1~experimental.1
> Severity: normal
> 
> I use dm-crypt on my system, and I have an SSD.  The underlying disk
> device, sda, has rotational=0:
> 
> ~$ cat /sys/block/sda/queue/rotational
> 0
> 
> However, the device-mapper devices have rotational=1:
> 
> ~$ head /sys/block/dm-*/queue/rotational
> ==> /sys/block/dm-0/queue/rotational <==
> 1
[...]
> The device-mapper devices should inherit the setting for "rotational"
> from their underlying devices.
> 
> - Josh Triplett

While I don't know about dm-crypt specifically, that issue should be 
fixed in 3.2~rc1:
	http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=4693c9668fdcec229825b3763876b4744f9e6d5e
(it is for plain lvm2, at least)

Regards
	Stefan Lippers-Hollmann