GRUB_DISABLE_RECOVERY="true"

[JD]

What is the significance/effect of setting
GRUB_DISABLE_RECOVERY=  to "true" or "false" ?

Thanx.

[Dennis Jacobfeuerborn]

On 07/20/2015 03:50 AM, jd1008 wrote:
> What is the significance/effect of setting
> GRUB_DISABLE_RECOVERY=  to "true" or "false" ?

Accroding to https://wiki.gentoo.org/wiki/GRUB2/Config_Variables :

"If true, recovery menu entries will not be generated. On Linux,
recovery entries pass "single" on the kernel command line."

Regards,
  Dennis

[JD]

On 07/20/2015 12:40 AM, Dennis Jacobfeuerborn wrote:
> On 07/20/2015 03:50 AM, jd1008 wrote:
> > What is the significance/effect of setting
> > GRUB_DISABLE_RECOVERY=  to "true" or "false" ?
>
> Accroding to https://wiki.gentoo.org/wiki/GRUB2/Config_Variables :
>
> "If true, recovery menu entries will not be generated. On Linux,
> recovery entries pass "single" on the kernel command line."
>
> Regards,
>    Dennis

Thank you Dennis, but that is still cryptic.

What are these recovery entries??
Do they refer to the grub boot entries, such as:
menuentry 'Fedora, with Linux 0-rescue-461e3f8f6eaa4c59a6eb26b2f67d5d0e' 
--class fedora --class gnu-linux --class gnu --class os 
$menuentry_id_option 
'gnulinux-0-rescue-461e3f8f6eaa4c59a6eb26b2f67d5d0e-advanced-5a038471-4aea-451f-b4ec-3f6b1e25bf1e' 
?

[Chris Murphy]

On Mon, Jul 20, 2015 at 10:49 AM, jd1008  wrote:
> On 07/20/2015 12:40 AM, Dennis Jacobfeuerborn wrote:
> > On 07/20/2015 03:50 AM, jd1008 wrote:
> > > What is the significance/effect of setting
> > > GRUB_DISABLE_RECOVERY=  to "true" or "false" ?
> >
> > Accroding to https://wiki.gentoo.org/wiki/GRUB2/Config_Variables :
> >
> > "If true, recovery menu entries will not be generated. On Linux,
> > recovery entries pass "single" on the kernel command line."
> >
> > Regards,
> >    Dennis
>
> Thank you Dennis, but that is still cryptic.

"single" on the kernel command line means single user mode boot.
> What are these recovery entries??
> Do they refer to the grub boot entries, such as:
> menuentry 'Fedora, with Linux 0-rescue-461e3f8f6eaa4c59a6eb26b2f67d5d0e'
> --class fedora --class gnu-linux --class gnu --class os $menuentry_id_option
> 'gnulinux-0-rescue-461e3f8f6eaa4c59a6eb26b2f67d5d0e-advanced-5a038471-4aea-451f-b4ec-3f6b1e25bf1e'

This GRUB setting has nothing to do with the rescue initramfs, which
is a nohostonly initramfs. The nohostonly "rescue" initramfs is, AFAIK
is a Fedora specific thing and I'm not sure if the responsible
upstream is the kernel team or dracut.

And yes, I find the terminology confusing, and actually the duplicate
use of the same term "rescue" for two different purposes in the
bootloader menu I think wasn't well thought out in advance.

There's the GRUB use of rescue which is single user mode.
There's the systemd use of rescue(.target) which is also single user
mode (in contrast to the even more rudimentary emergency.target)
There's the kernel rpm/dracut use of rescue which is a nohostonly initramfs.

Let's see what else uses rescue? btrfs rescue zero-log is a stretch...

[JD]

On 07/20/2015 11:04 AM, Chris Murphy wrote:
> On Mon, Jul 20, 2015 at 10:49 AM, jd1008  wrote:
> > On 07/20/2015 12:40 AM, Dennis Jacobfeuerborn wrote:
> > > On 07/20/2015 03:50 AM, jd1008 wrote:
> > > > What is the significance/effect of setting
> > > > GRUB_DISABLE_RECOVERY=  to "true" or "false" ?
> > >
> > > Accroding to https://wiki.gentoo.org/wiki/GRUB2/Config_Variables :
> > >
> > > "If true, recovery menu entries will not be generated. On Linux,
> > > recovery entries pass "single" on the kernel command line."
> > >
> > > Regards,
> > >     Dennis
> >
> > Thank you Dennis, but that is still cryptic.
>
> "single" on the kernel command line means single user mode boot.
> > What are these recovery entries??
> > Do they refer to the grub boot entries, such as:
> > menuentry 'Fedora, with Linux 0-rescue-461e3f8f6eaa4c59a6eb26b2f67d5d0e'
> > --class fedora --class gnu-linux --class gnu --class os $menuentry_id_option
> > 'gnulinux-0-rescue-461e3f8f6eaa4c59a6eb26b2f67d5d0e-advanced-5a038471-4aea-451f-b4ec-3f6b1e25bf1e'
>
> This GRUB setting has nothing to do with the rescue initramfs, which
> is a nohostonly initramfs. The nohostonly "rescue" initramfs is, AFAIK
> is a Fedora specific thing and I'm not sure if the responsible
> upstream is the kernel team or dracut.
>
> And yes, I find the terminology confusing, and actually the duplicate
> use of the same term "rescue" for two different purposes in the
> bootloader menu I think wasn't well thought out in advance.
>
> There's the GRUB use of rescue which is single user mode.
> There's the systemd use of rescue(.target) which is also single user
> mode (in contrast to the even more rudimentary emergency.target)
> There's the kernel rpm/dracut use of rescue which is a nohostonly initramfs.
>
> Let's see what else uses rescue? btrfs rescue zero-log is a stretch...

How in tarnation are newbs going to deal with this? :)
I truly hesitate to recommend Fedora to my *indoze users buddies :)

[Gordon Messmer]

On 07/20/2015 10:22 AM, jd1008 wrote:
> How in tarnation are newbs going to deal with this? :)

By leaving the defaults alone?

Seriously, there is no significant OS that doesn't have advanced options 
that would confuse "newbs".

[Tom Horsley]

On Mon, 20 Jul 2015 10:49:16 -0600
jd1008 wrote:
> What are these recovery entries??

If I'm recalling correctly (and I'm probably not :-), this
has something to do with grub acting different if it fails
to boot for some reason. I ran into this a lot on virtual
machines which were supposed to come up automatically, but
"helpful" grub error recovery would disable automatic
booting and leave you in a grub prompt if it wasn't able
to boot properly once, so as soon as a virtual machine
had a problem booting, it would never boot again without
manual intervention (so helpful that was).