[gentoo-user] loop devices not present

[gentoo-user] loop devices not present

[Alan McKinnon]

Hi all,

Kernel 2.6.20-gentoo

My various /dev/loop/* devices used to always JustWork, until a recent 
update. Unfortunately I can't tell when the breakage happened.

Right now what happens is I don't get these devices automatically 
and 'mount - o loop' fails. A simple 'modprobe loop' fixes this, the 
kernel is configured as I've been using it for ages:

config-2.6.20-gentoo:CONFIG_BLK_DEV_LOOP=m
config-2.6.20-gentoo:CONFIG_KMOD=y

Oddly, I never had 'loop' in /etc/modules.autoload.d/kernel-2.6 before 
(I do now), anyone know of a recent change that would cause this?

alan

-- 
Optimists say the glass is half full,
Pessimists say the glass is half empty,
Developers say wtf is the glass twice as big as it needs to be?

Alan McKinnon
alan at linuxholdings dot co dot za
+27 82, double three seven, one nine three five
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Re: [gentoo-user] loop devices not present

[Walter Dnes]

On Mon, Feb 19, 2007 at 12:35:13PM +0200, Alan McKinnon wrote
> Hi all,
> 
> Kernel 2.6.20-gentoo
> 
> My various /dev/loop/* devices used to always JustWork, until a recent 
> update. Unfortunately I can't tell when the breakage happened.
> 
> Right now what happens is I don't get these devices automatically 
> and 'mount - o loop' fails. A simple 'modprobe loop' fixes this, the 
> kernel is configured as I've been using it for ages:
> 
> config-2.6.20-gentoo:CONFIG_BLK_DEV_LOOP=m
> config-2.6.20-gentoo:CONFIG_KMOD=y
> 
> Oddly, I never had 'loop' in /etc/modules.autoload.d/kernel-2.6 before 
> (I do now), anyone know of a recent change that would cause this?

  If you want loopback devices to "just work", they should be compiled
into the kernel, like so...

make menuconfig
Device Drivers  --->
Block devices  --->
<*> Loopback device support

  My guess is that somewhere along the line, the "<*>" got changed to a
"<M>".  Change it back to "<*>", recompile the kernel and any necessary
modules, and reboot.

-- 
Walter Dnes <waltdnes@waltdnes.org> In linux /sbin/init is Job #1
My musings on technology and security at http://techsec.blog.ca
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Re: [gentoo-user] loop devices not present

[Alan McKinnon]

On Wednesday 21 February 2007, Walter Dnes wrote:
>   If you want loopback devices to "just work", they should be
> compiled into the kernel, like so...
>
> make menuconfig
> Device Drivers  --->
> Block devices  --->
> <*> Loopback device support
>
>   My guess is that somewhere along the line, the "<*>" got changed to
> a "<M>".  Change it back to "<*>", recompile the kernel and any
> necessary modules, and reboot.

That would be true except I've beeen setting loop to <M> since many 
kernel versions back.  I actually suspect it's more a udev thing, there 
has been a lot of activity and changes with the rules recently. But I'm 
too rushed to decrypt all the rules syntax and see what changed.

In a way it makes sense to make udev not create loop devices by default. 
If the user didn't ask for them, they shouldn't be there (aka 
TheGentooWay). And 'loop' in kernel-2.6 fixes it all. 

Thanks for replying,

alan



-- 
Optimists say the glass is half full,
Pessimists say the glass is half empty,
Developers say wtf is the glass twice as big as it needs to be?

Alan McKinnon
alan at linuxholdings dot co dot za
+27 82, double three seven, one nine three five
--
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Re: [gentoo-user] loop devices not present

[Neil Bothwick]

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On Wed, 21 Feb 2007 09:51:45 +0200, Alan McKinnon wrote:

> That would be true except I've beeen setting loop to <M> since many 
> kernel versions back.  I actually suspect it's more a udev thing, there 
> has been a lot of activity and changes with the rules recently. But I'm 
> too rushed to decrypt all the rules syntax and see what changed.

My loop devices disappeared like this some time ago - are you using
stable? I initially put loop in modules.autoload.d but since I use loop
devices every time I boot, I moved them into the kernel instead.


-- 
Neil Bothwick

Plagarism prohibited. Derive carefully.

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Re: [gentoo-user] loop devices not present

[Alan McKinnon]

On Wednesday 21 February 2007, Neil Bothwick wrote:
> On Wed, 21 Feb 2007 09:51:45 +0200, Alan McKinnon wrote:
> > That would be true except I've beeen setting loop to <M> since many
> > kernel versions back.  I actually suspect it's more a udev thing,
> > there has been a lot of activity and changes with the rules
> > recently. But I'm too rushed to decrypt all the rules syntax and
> > see what changed.
>
> My loop devices disappeared like this some time ago - are you using
> stable? I initially put loop in modules.autoload.d but since I use
> loop devices every time I boot, I moved them into the kernel instead.

No, I'm using ~x86.

I got things to a satisfactory state using modules.autoload.d just like 
you and get the best of both worlds.

thanks

alan



-- 
Optimists say the glass is half full,
Pessimists say the glass is half empty,
Developers say wtf is the glass twice as big as it needs to be?

Alan McKinnon
alan at linuxholdings dot co dot za
+27 82, double three seven, one nine three five
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