Searching UUID on floppies

Searching UUID on floppies

[Pavel Roskin]

Hello!

An old system with a floppy drive has a minor regression with the
current GRUB.  It makes some noises for a second or two when GRUB loads,
apparently trying to find a floppy disk in the drive.

It's possible that some misconfigured systems may even hang or wait for
a long time if the floppy drive is absent, but BIOS expects it to be
present.  It's easy to blame users, but it will be seen as a regression.

Perhaps the UUID search should start with the hard drives and then go to
the floppies as the last resort?

-- 
Regards,
Pavel Roskin

Re: Searching UUID on floppies

[Bean]

On Sat, May 31, 2008 at 6:14 AM, Pavel Roskin <proski@gnu.org> wrote:
> Hello!
>
> An old system with a floppy drive has a minor regression with the
> current GRUB.  It makes some noises for a second or two when GRUB loads,
> apparently trying to find a floppy disk in the drive.
>
> It's possible that some misconfigured systems may even hang or wait for
> a long time if the floppy drive is absent, but BIOS expects it to be
> present.  It's easy to blame users, but it will be seen as a regression.
>
> Perhaps the UUID search should start with the hard drives and then go to
> the floppies as the last resort?

Good point, but I think we shouldn't hard coded the scan method in
search. Perhaps we can add a option to search to skip some device,
something such as:

search --ignore-device=fd /file

Or we can use a variable like:

noscan=fd

The advantage of using variable is that we can use it in findroot as well.

-- 
Bean

Re: Searching UUID on floppies

[Bean]

On Sat, May 31, 2008 at 1:38 PM, Bean <bean123ch@gmail.com> wrote:
> On Sat, May 31, 2008 at 6:14 AM, Pavel Roskin <proski@gnu.org> wrote:
>> Hello!
>>
>> An old system with a floppy drive has a minor regression with the
>> current GRUB.  It makes some noises for a second or two when GRUB loads,
>> apparently trying to find a floppy disk in the drive.
>>
>> It's possible that some misconfigured systems may even hang or wait for
>> a long time if the floppy drive is absent, but BIOS expects it to be
>> present.  It's easy to blame users, but it will be seen as a regression.
>>
>> Perhaps the UUID search should start with the hard drives and then go to
>> the floppies as the last resort?
>
> Good point, but I think we shouldn't hard coded the scan method in
> search. Perhaps we can add a option to search to skip some device,
> something such as:
>
> search --ignore-device=fd /file
>
> Or we can use a variable like:
>
> noscan=fd
>
> The advantage of using variable is that we can use it in findroot as well.

BTW, if you merely need to change the scan order instead of disabling
it, you can just change the order the device is reported in biosdisk.

-- 
Bean

Re: Searching UUID on floppies

[Robert Millan]

On Sat, May 31, 2008 at 01:43:13PM +0800, Bean wrote:
> 
> BTW, if you merely need to change the scan order instead of disabling
> it, you can just change the order the device is reported in biosdisk.

Sounds nice.  I see you already included this change with your patch in
the "findroot" thread.  Do you mind if we check this in before resolving
the other stuff?  I uploaded the UUID-capable version to Debian yesterday
and almost can hear the users complaining about annoying floppy probes ;-)

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What good is a phone call… if you are unable to speak?
(as seen on /.)

Re: Searching UUID on floppies

[Bean]

On Sun, Jun 1, 2008 at 3:30 AM, Robert Millan <rmh@aybabtu.com> wrote:
> On Sat, May 31, 2008 at 01:43:13PM +0800, Bean wrote:
>>
>> BTW, if you merely need to change the scan order instead of disabling
>> it, you can just change the order the device is reported in biosdisk.
>
> Sounds nice.  I see you already included this change with your patch in
> the "findroot" thread.  Do you mind if we check this in before resolving
> the other stuff?  I uploaded the UUID-capable version to Debian yesterday
> and almost can hear the users complaining about annoying floppy probes ;-)

Feel free to commit it.

-- 
Bean

Re: Searching UUID on floppies

[Robert Millan]

On Sat, May 31, 2008 at 01:38:07PM +0800, Bean wrote:
> On Sat, May 31, 2008 at 6:14 AM, Pavel Roskin <proski@gnu.org> wrote:
> > Hello!
> >
> > An old system with a floppy drive has a minor regression with the
> > current GRUB.  It makes some noises for a second or two when GRUB loads,
> > apparently trying to find a floppy disk in the drive.
> >
> > It's possible that some misconfigured systems may even hang or wait for
> > a long time if the floppy drive is absent, but BIOS expects it to be
> > present.  It's easy to blame users, but it will be seen as a regression.
> >
> > Perhaps the UUID search should start with the hard drives and then go to
> > the floppies as the last resort?
> 
> Good point, but I think we shouldn't hard coded the scan method in
> search. Perhaps we can add a option to search to skip some device,
> something such as:
> 
> search --ignore-device=fd /file
> 
> Or we can use a variable like:
> 
> noscan=fd
> 
> The advantage of using variable is that we can use it in findroot as well.

Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 'find'
or so, can't remember).  Perhaps it's better to use that for consistency?  It
is the floppy scan which everyone hates; for other devices I don't think
people will mind if GRUB spends a few ms on them.

./util/i386/pc/grub-install.in:  --no-floppy             do not probe any floppy drive
./util/i386/pc/grub-install.in:    --no-floppy)
./util/i386/pc/grub-install.in: no_floppy="--no-floppy" ;;
./util/i386/efi/grub-install.in:  --no-floppy             do not probe any floppy drive
./util/i386/efi/grub-install.in:    --no-floppy)
./util/i386/efi/grub-install.in:        no_floppy="--no-floppy" ;;
./util/grub-mkdevicemap.c:    {"no-floppy", no_argument, 0, 'n'},
./util/grub-mkdevicemap.c:  -n, --no-floppy           do not probe any floppy drive\n\
./docs/grub.texi:@item --no-floppy

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What good is a phone call… if you are unable to speak?
(as seen on /.)

Re: Searching UUID on floppies

[Isaac Dupree]

Robert Millan wrote:
> Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 'find'
> or so, can't remember).  Perhaps it's better to use that for consistency?  It
> is the floppy scan which everyone hates; for other devices I don't think
> people will mind if GRUB spends a few ms on them.

I don't know if it's relevant... but there is a situation that is maybe 
similar when my MacBook boots up (before it even gets to GRUB), if 
there's a CD in the drive, it wastes about 15 extra seconds spinning it 
up to look at it, even if I'm not booting from CD.  So that might be a 
sort of thing to watch out for, when making GRUB search?

-Isaac

Re: Searching UUID on floppies

[Robert Millan]

On Sat, May 31, 2008 at 03:06:30PM -0400, Isaac Dupree wrote:
> Robert Millan wrote:
> >Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 
> >'find'
> >or so, can't remember).  Perhaps it's better to use that for consistency?  
> >It
> >is the floppy scan which everyone hates; for other devices I don't think
> >people will mind if GRUB spends a few ms on them.
> 
> I don't know if it's relevant... but there is a situation that is maybe 
> similar when my MacBook boots up (before it even gets to GRUB), if 
> there's a CD in the drive, it wastes about 15 extra seconds spinning it 
> up to look at it, even if I'm not booting from CD.  So that might be a 
> sort of thing to watch out for, when making GRUB search?

Does it happen before or after you get the "Welcome to GRUB!" message?

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What good is a phone call… if you are unable to speak?
(as seen on /.)

Re: Searching UUID on floppies

[Isaac Dupree]

Robert Millan wrote:
> On Sat, May 31, 2008 at 03:06:30PM -0400, Isaac Dupree wrote:
>> Robert Millan wrote:
>>> Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 
>>> 'find'
>>> or so, can't remember).  Perhaps it's better to use that for consistency?  
>>> It
>>> is the floppy scan which everyone hates; for other devices I don't think
>>> people will mind if GRUB spends a few ms on them.
>> I don't know if it's relevant... but there is a situation that is maybe 
>> similar when my MacBook boots up (before it even gets to GRUB), if 
>> there's a CD in the drive, it wastes about 15 extra seconds spinning it 
>> up to look at it, even if I'm not booting from CD.  So that might be a 
>> sort of thing to watch out for, when making GRUB search?
> 
> Does it happen before or after you get the "Welcome to GRUB!" message?

*That* happens even if I never enter grub at all -- so I guess you would 
say "before".  GRUB doesn't have that problem for me as far as I know, 
but the only things I have in my config are (hd0,x) -- no boot-from-CD 
option, only the Linuxes on the disk that I have configured precisely 
and numerically.

look, here is my boot sequence:
EFI firmware boots the MacOSX partition by default, if I don't hold down 
"option"/"alt" (if I do, then the firmware puts up a menu of choices).

rEFIt is installed in such a way that it is booted rather the standard 
MacOSX at that point.  It puts up a nice menu of choices including 
MacOS, any bootable CD/DVDs, and all the GRUBs it can find.  It's 
rEFIt's appearance that is delayed when there's a CD in the drive. 
rEFIt knows how to boot both EFI and BIOS GRUBs.
-- MacOSX: boots normally if selected in rEFIt.
-- GRUB2: well, you know about that.  From there, I can potentially boot 
my Linuxes that are on various of my partitions.


-Isaac

Re: Searching UUID on floppies

[Robert Millan]

On Sat, May 31, 2008 at 05:56:59PM -0400, Isaac Dupree wrote:
> Robert Millan wrote:
> >On Sat, May 31, 2008 at 03:06:30PM -0400, Isaac Dupree wrote:
> >>Robert Millan wrote:
> >>>Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 
> >>>'find'
> >>>or so, can't remember).  Perhaps it's better to use that for 
> >>>consistency?  It
> >>>is the floppy scan which everyone hates; for other devices I don't think
> >>>people will mind if GRUB spends a few ms on them.
> >>I don't know if it's relevant... but there is a situation that is maybe 
> >>similar when my MacBook boots up (before it even gets to GRUB), if 
> >>there's a CD in the drive, it wastes about 15 extra seconds spinning it 
> >>up to look at it, even if I'm not booting from CD.  So that might be a 
> >>sort of thing to watch out for, when making GRUB search?
> >
> >Does it happen before or after you get the "Welcome to GRUB!" message?
> 
> *That* happens even if I never enter grub at all -- so I guess you would 
> say "before".  GRUB doesn't have that problem for me as far as I know, 
> but the only things I have in my config are (hd0,x) -- no boot-from-CD 
> option, only the Linuxes on the disk that I have configured precisely 
> and numerically.

Definitely not a GRUB bug, then ;-)

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What good is a phone call… if you are unable to speak?
(as seen on /.)

Re: Searching UUID on floppies

[Pavel Roskin]

On Sat, 2008-05-31 at 11:53 +0200, Robert Millan wrote:

> Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 'find'
> or so, can't remember).  Perhaps it's better to use that for consistency?  It
> is the floppy scan which everyone hates; for other devices I don't think
> people will mind if GRUB spends a few ms on them.

Sure, --no-floppy would be consistent with the installers, but it will
take some effort to get right.  Let's not forget CD floppy emulation, by
the way.  You wrote that sometimes a hard drive can be reported as a
floppy.  Perhaps we still want to search floppies as the last resort.

Besides, I'd prefer to avoid floppy search is all "search" commands.  I
have a custom rule to boot another distro, and it uses "search" by
label.  I don't want to add --no-floppy to that command because it's an
extra effort.  It's not hard for GRUB to do things nicely without having
users edit their custom rules.

That's why I would prefer optimized search order.  But I'm not strongly
opposing --no-floppy as long as it's done right.

We could also start search with the current drive and then go through
the list of other drives, without changing anything else in the order.
Most installations will rely on one disk.  Spinning up more devices
unnecessarily is not nice.

-- 
Regards,
Pavel Roskin

Re: Searching UUID on floppies

[Robert Millan]

On Sun, Jun 01, 2008 at 02:19:27AM -0400, Pavel Roskin wrote:
> On Sat, 2008-05-31 at 11:53 +0200, Robert Millan wrote:
> 
> > Some of our commands use --no-floppy.  Also supported in GRUB Legacy (by 'find'
> > or so, can't remember).  Perhaps it's better to use that for consistency?  It
> > is the floppy scan which everyone hates; for other devices I don't think
> > people will mind if GRUB spends a few ms on them.
> 
> Sure, --no-floppy would be consistent with the installers, but it will
> take some effort to get right.  Let's not forget CD floppy emulation, by
> the way.  You wrote that sometimes a hard drive can be reported as a
> floppy.  Perhaps we still want to search floppies as the last resort.
> 
> Besides, I'd prefer to avoid floppy search is all "search" commands.  I
> have a custom rule to boot another distro, and it uses "search" by
> label.  I don't want to add --no-floppy to that command because it's an
> extra effort.  It's not hard for GRUB to do things nicely without having
> users edit their custom rules.
> 
> That's why I would prefer optimized search order.  But I'm not strongly
> opposing --no-floppy as long as it's done right.

Search order has been optimized now (see the other sub-thread).  But there's
still room for improvement, of course..

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What good is a phone call… if you are unable to speak?
(as seen on /.)