[DNG] Installing without rebooting
With all this discussion about installing procedures, why do we need to reboot during reboot ? Couldn't one boot the install media like an initram thing and then pivot_root (or what is used today) the real system and continuing from there... I did some experiments some ten years ago, but run out of cds. Even if it isn't in the end useful, isn't it fun to show off. Regards, /Karl Hammar --- Aspö Data Lilla Aspö 148 S-742 94 Östhammar Sweden ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On Tue, 18 Dec 2018 23:33:30 +0100 (CET) k...@aspodata.se wrote: > With all this discussion about installing procedures, why do we need > to reboot during reboot ? > > Couldn't one boot the install media like an initram thing and then > pivot_root (or what is used today) the real system and continuing > from there... I don't ever want to encourage use of initramfs. Down that road lies Redhat. SteveT Steve Litt December 2018 featured book: Rapid Learning for the 21st Century http://www.troubleshooters.com/rl21 ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Because you're not necessarily installing the same API. ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Steve Litt: ... > I don't ever want to encourage use of initramfs. Down that road lies > Redhat. ... It's a tool in the toolbox, useful sometimes and not necessary sometimes. Regards, /Karl Hammar --- Aspö Data Lilla Aspö 148 S-742 94 Östhammar Sweden ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Bruce Perens: > Because you're not necessarily installing the same API. And by API, you mean the system calls that the used kernel make available and the clib used ? Regards, /Karl Hammar --- Aspö Data Lilla Aspö 148 S-742 94 Östhammar Sweden ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On Wed, Dec 19, 2018 at 12:09:29AM -0500, Steve Litt wrote: > On Tue, 18 Dec 2018 23:33:30 +0100 (CET) > k...@aspodata.se wrote: > > > With all this discussion about installing procedures, why do we need > > to reboot during reboot ? > > > > Couldn't one boot the install media like an initram thing and then > > pivot_root (or what is used today) the real system and continuing > > from there... > > I don't ever want to encourage use of initramfs. Down that road lies > Redhat. It's not possible to pivot_root away from the install USB to the installed root system on rotating rust (or whatever permannt storage the computer has? Does this have anything to do with initramfs? It would probably constrain the installer to use the same kernel as the installee, though. Which means lots of installer versions. -- hendrik ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Hendrik: > On Wed, Dec 19, 2018 at 12:09:29AM -0500, Steve Litt wrote: > > On Tue, 18 Dec 2018 23:33:30 +0100 (CET) > > k...@aspodata.se wrote: > > > > > With all this discussion about installing procedures, why do we need > > > to reboot during reboot ? I meant: to reboot during install ? > > > Couldn't one boot the install media like an initram thing and then > > > pivot_root (or what is used today) the real system and continuing > > > from there... ... > It's not possible to pivot_root away from the install USB to the > installed root system on rotating rust (or whatever permannt storage > the computer has? Ok. > Does this have anything to do with initramfs? Possibly not, but initramfs/initrd does that all the times, i.e. during boot, do something and then switch to installed system. > It would probably constrain the installer to use the same kernel as the > installee, though. Which means lots of installer versions. Yes, but this was meant as a "research" project, is it possible and if so, what are the consequences. /// One possible way to test this could be to have a greatly simplified installer in an initramfs/initrd, which basically does a "precompiled" install to a known system, and then switches to it and possible continues from that. Regards, /Karl Hammar --- Aspö Data Lilla Aspö 148 S-742 94 Östhammar Sweden ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
There is this notion of "kexec boot"; I've never tried it, but it's documentation claims "kexec is a system call that enables you to load and boot into another kernel from the currently running kernel." Maybe it comes with too many ifs and buts to be a viable approach. Ralph. k...@aspodata.se wrote on 20/12/18 00:36: > Hendrik: >> On Wed, Dec 19, 2018 at 12:09:29AM -0500, Steve Litt wrote: >>> On Tue, 18 Dec 2018 23:33:30 +0100 (CET) >>> k...@aspodata.se wrote: >>> With all this discussion about installing procedures, why do we need to reboot during reboot ? > I meant: to reboot during install ? Couldn't one boot the install media like an initram thing and then pivot_root (or what is used today) the real system and continuing from there... > ... >> It's not possible to pivot_root away from the install USB to the >> installed root system on rotating rust (or whatever permannt storage >> the computer has? > > Ok. > >> Does this have anything to do with initramfs? > > Possibly not, but initramfs/initrd does that all the times, i.e. > during boot, do something and then switch to installed system. > >> It would probably constrain the installer to use the same kernel as the >> installee, though. Which means lots of installer versions. > > Yes, but this was meant as a "research" project, is it possible and if > so, what are the consequences. > > /// > > One possible way to test this could be to have a greatly simplified > installer in an initramfs/initrd, which basically does a "precompiled" > install to a known system, and then switches to it and possible > continues from that. > > Regards, > /Karl Hammar > > --- > Aspö Data > Lilla Aspö 148 > S-742 94 Östhammar > Sweden > > > ___ > Dng mailing list > Dng@lists.dyne.org > https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng > ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On Thu, 20 Dec 2018 00:59:35 +1100, Ralph wrote in message : > There is this notion of "kexec boot"; I've never tried it, but it's > documentation claims "kexec is a system call that enables you to > load and boot into another kernel from the currently running kernel." > > Maybe it comes with too many ifs and buts to be a viable approach. > > Ralph. ..I used to "kexec reboot" a lot in my pre-systemd Debian days, AFAIR, bought me nice long uptimes with new kernels. ;o) -- ..med vennlig hilsen = with Kind Regards from Arnt Karlsen ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Le 20/12/2018 à 15:32, Arnt Karlsen a écrit : On Thu, 20 Dec 2018 00:59:35 +1100, Ralph wrote in message : There is this notion of "kexec boot"; I've never tried it, but it's documentation claims "kexec is a system call that enables you to load and boot into another kernel from the currently running kernel." Maybe it comes with too many ifs and buts to be a viable approach. Ralph. ..I used to "kexec reboot" a lot in my pre-systemd Debian days, AFAIR, bought me nice long uptimes with new kernels. ;o) What's the purpose of kexec ? I see one main: using a Linux session as the bootloader, a bootloader more heavily customizable than Grub. Additionally it saves a few seconds. Are there any other ? Didier ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On Thu, Dec 20, 2018 at 03:38:01PM +0100, Didier Kryn wrote: > Le 20/12/2018 à 15:32, Arnt Karlsen a écrit : > > On Thu, 20 Dec 2018 00:59:35 +1100, Ralph wrote in message > > : > > > > > There is this notion of "kexec boot"; I've never tried it, but it's > > > documentation claims "kexec is a system call that enables you to > > > load and boot into another kernel from the currently running kernel." > > > > > > Maybe it comes with too many ifs and buts to be a viable approach. > > > > > > Ralph. > > ..I used to "kexec reboot" a lot in my pre-systemd Debian days, > > AFAIR, bought me nice long uptimes with new kernels. ;o) > > > What's the purpose of kexec ? I see one main: using a Linux session as > the bootloader, a bootloader more heavily customizable than Grub. > Additionally it saves a few seconds. Are there any other ? Post-mortem on a crashed system: the second kernel can access the whole memory, etc. It can also bring you some "fun" when it turns out the machine can't boot from a cold start. Meow! -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢠⠒⠀⣿⡁ Ivan was a worldly man: born in St. Petersburg, raised in ⢿⡄⠘⠷⠚⠋⠀ Petrograd, lived most of his life in Leningrad, then returned ⠈⠳⣄ to the city of his birth to die. ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Le 20/12/2018 à 16:22, Adam Borowski a écrit : On Thu, Dec 20, 2018 at 03:38:01PM +0100, Didier Kryn wrote: What's the purpose of kexec ? I see one main: using a Linux session as the bootloader, a bootloader more heavily customizable than Grub. Additionally it saves a few seconds. Are there any other ? Post-mortem on a crashed system: the second kernel can access the whole memory, etc. It can also bring you some "fun" when it turns out the machine can't boot from a cold start. In the last case you assume you have realized that the machine can't coldstart before experimenting it (~: Didier ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On Thu, 20 Dec 2018 15:38:01 +0100 Didier Kryn wrote: > What's the purpose of kexec ? I see one main: using a Linux > session as the bootloader, a bootloader more heavily customizable > than Grub. Additionally it saves a few seconds. Are there any other ? > > Didier Wow. Are you saying I can get rid of Grub? Can I use kexec to boot to an mbr, with no UEFI in sight? If so, I'm on it like a squirrel on a tree. Can kexec boot with or from UEFI? If so, I'm on it like a squirrel on a tree. I'm not a fan of grub2. SteveT Steve Litt December 2018 featured book: Rapid Learning for the 21st Century http://www.troubleshooters.com/rl21 ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
Le 20/12/2018 à 23:50, Steve Litt a écrit : Didier Kryn wrote: What's the purpose of kexec ? I see one main: using a Linux session as the bootloader, a bootloader more heavily customizable than Grub. Additionally it saves a few seconds. Are there any other ? Didier Wow. Are you saying I can get rid of Grub? No, sorry, it's still necessary to boot the first one. You use grub (or syslinux, why not ?) to boot the first kernel; then from this one you kexec a second one. This is only if you want a lot of flexibility and variety in the choice of the second one. The first Linux OS can run a custom application to select the second one and pass it the custom command-line arguments. There should be a serious need to do this kind of hack (~: ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On 20/12/18 at 15:32, Arnt Karlsen wrote: > On Thu, 20 Dec 2018 00:59:35 +1100, Ralph wrote in message > : > >> There is this notion of "kexec boot"; I've never tried it, but it's >> documentation claims "kexec is a system call that enables you to >> load and boot into another kernel from the currently running kernel." >> >> Maybe it comes with too many ifs and buts to be a viable approach. >> >> Ralph. > ..I used to "kexec reboot" a lot in my pre-systemd Debian days, > AFAIR, bought me nice long uptimes with new kernels. ;o) AFAIR, uptime is not maintained through a kexec. -- Alessandro Selli VOIP SIP: dhatarat...@ekiga.net Chiave firma e cifratura PGP/GPG signing and encoding key: BA651E4050DDFC31E17384BABCE7BD1A1B0DF2AE signature.asc Description: OpenPGP digital signature ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] Installing without rebooting
On Fri, 21 Dec 2018 21:30:17 +0100, Alessandro wrote in message : > On 20/12/18 at 15:32, Arnt Karlsen wrote: > > On Thu, 20 Dec 2018 00:59:35 +1100, Ralph wrote in message > > : > > > >> There is this notion of "kexec boot"; I've never tried it, but it's > >> documentation claims "kexec is a system call that enables you to > >> load and boot into another kernel from the currently running > >> kernel." > >> > >> Maybe it comes with too many ifs and buts to be a viable approach. > >> > >> Ralph. > > ..I used to "kexec reboot" a lot in my pre-systemd Debian days, > > AFAIR, bought me nice long uptimes with new kernels. ;o) > > > AFAIR, uptime is not maintained through a kexec. ..I agree it shouldn't be, and I'm not sure what went wrong, it's like 10 years ago, but I do have the hardware in one of my 3 20-feeters and I need a lawsuit win in mid february to find a place to live and reproduce this bug. -- ..med vennlig hilsen = with Kind Regards from Arnt Karlsen ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
