Re: [gentoo-user] Re: Safe way to test a new kernel?
On Sun 26 Feb 2012 08:05:23 PM IST, Grant wrote: >>> I get "Unrecognized command" from savedefault in grub: >>> >>> grub> savedefault --default=1 --once >>> Error 27: Unrecognized command >> >> Strange. Maybe this is something inofficial, and not every Gurb >> understands this? The documentation does not mention the --default option >> I think. >> >>> I re-emerged grub with /boot mounted and ran grub-install but I get >>> the same error. Does anyone know how to fix this? I'm on >>> grub-0.97-r10. >> >> Have a look at 'info grub', 'Booting' -> 'Making your system robust', >> especially section 4.3.2 'Booting fallback systems'. That's what I used in >> order to test new kernels remotely. >> >>Wonko > > I like that better. Where do you execute 'grub-set-default 0'? > > I did notice this: > > "In some newer versions of GNU/Linux, there is no > /sbin/grub-set-default (eg. Debian 3.1, Fedora Core 4,5). While some > distributions like Gentoo still has /sbin/grub-set-default" > > http://sidvind.com/wiki/GRUB:_Boot_another_OS_once#Method_1_.28preferred.29 > > BTW, is there a way to tell which grub entry I'm booted into, or am I > best off examining the contents of /proc/config.gz? > > - Grant > uname -r If the kernel version is same, add a version string in menuconfig. -- Nilesh Govindarajan http://nileshgr.com
Re: [gentoo-user] Re: Safe way to test a new kernel?
Grant writes: > > Have a look at 'info grub', 'Booting' -> 'Making your system robust', > > especially section 4.3.2 'Booting fallback systems'. That's what I > > used in order to test new kernels remotely. > > > > Wonko > > I like that better. Where do you execute 'grub-set-default 0'? I had it in /etc/init.d/local.start back when I used these features. Nowadays with openrc I would put this line in /etc/local.d/grub-default.start. I had some safety checks included, like testing if networking and sshd was running, so this box would be accessible from remote. But this is some years ago now, currently I do not administrate such remote servers and so I have not used this mechanism for a while. > BTW, is there a way to tell which grub entry I'm booted into, or am I > best off examining the contents of /proc/config.gz? The first line in /boot/grub/default has the number of the default entry. grub-set-default modifies this file, as does the GRUB savedefault command. Wonko
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> I get "Unrecognized command" from savedefault in grub: >> >> grub> savedefault --default=1 --once >> Error 27: Unrecognized command > > Strange. Maybe this is something inofficial, and not every Gurb > understands this? The documentation does not mention the --default option > I think. > >> I re-emerged grub with /boot mounted and ran grub-install but I get >> the same error. Does anyone know how to fix this? I'm on >> grub-0.97-r10. > > Have a look at 'info grub', 'Booting' -> 'Making your system robust', > especially section 4.3.2 'Booting fallback systems'. That's what I used in > order to test new kernels remotely. > > Wonko I like that better. Where do you execute 'grub-set-default 0'? I did notice this: "In some newer versions of GNU/Linux, there is no /sbin/grub-set-default (eg. Debian 3.1, Fedora Core 4,5). While some distributions like Gentoo still has /sbin/grub-set-default" http://sidvind.com/wiki/GRUB:_Boot_another_OS_once#Method_1_.28preferred.29 BTW, is there a way to tell which grub entry I'm booted into, or am I best off examining the contents of /proc/config.gz? - Grant
Re: [gentoo-user] Re: Safe way to test a new kernel?
Grant writes: > I get "Unrecognized command" from savedefault in grub: > > grub> savedefault --default=1 --once > Error 27: Unrecognized command Strange. Maybe this is something inofficial, and not every Gurb understands this? The documentation does not mention the --default option I think. > I re-emerged grub with /boot mounted and ran grub-install but I get > the same error. Does anyone know how to fix this? I'm on > grub-0.97-r10. Have a look at 'info grub', 'Booting' -> 'Making your system robust', especially section 4.3.2 'Booting fallback systems'. That's what I used in order to test new kernels remotely. Wonko
Re: [gentoo-user] Re: Safe way to test a new kernel?
>>> I need to test a kernel config change on a remote system. Is there a >>> safe way to do this? The fallback thing in grub has never worked for >>> me. When does that ever work? >> >> >> Oh crap, you said "remote system". Somehow I missed that. Ignore my >> previous post since obviously accessing Grub on a remote machine would >> require a hardware VNC module (if you had that, then you wouldn't have >> posted about the issue in the first place, I assume.) >> >> The way I dealt with it, is to use the "boot once" functionality of Grub: >> >> http://weichong78.blogspot.com/2007/04/grub-test-kernel-once.html > > Perfect! That's exactly what I need. Here is an alternate method too: > > http://fabbritech.blogspot.com/2009/07/make-grub-boot-something-once.html > > I will test this ASAP. > > - Grant I get "Unrecognized command" from savedefault in grub: grub> savedefault --default=1 --once Error 27: Unrecognized command I re-emerged grub with /boot mounted and ran grub-install but I get the same error. Does anyone know how to fix this? I'm on grub-0.97-r10. - Grant
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Sun, 26 Feb 2012 02:50:46 +0700 Pandu Poluan wrote: > So, as you can see, binary distros can still fuck up royal time. Not > to mention that if you have an exotic configuration, support for your > configuration might not be built into the kernel by the distro. > > Somehow I believe people deploying Gentoo servers will be much more > careful... > Oh, the people who deploy Gentoo are certainly that careful. It's the junior admins who type "emerge world" and walk away that aren't up to the task. I sadly had to ban Gentoo on production at work for that reason, but it's still highly recommended for -dev and -stage machines. -- Alan McKinnnon alan.mckin...@gmail.com
Re: [gentoo-user] Re: Safe way to test a new kernel?
V Sun, 26 Feb 2012 02:50:46 +0700 Pandu Poluan napsáno: > On Feb 26, 2012 2:05 AM, "Robert David" > wrote: > > > > V Sat, 25 Feb 2012 10:32:20 -0800 > > Grant napsáno: > > > > > >> >> I need to test a kernel config change on a remote system. > > > >> >> Is there a safe way to do this? The fallback thing in grub > > > >> >> has never worked for me. When does that ever work? > > > >> > > > > >> > > > > >> > You can press ESC in the Grub screen and it will take you to > > > >> > text-only mode. There, you select an entry, press "e" and > > > >> > edit it. Press ENTER when you're finished, and then press > > > >> > "b" to boot your modified entry. > > > >> > > > > >> > That way, you can boot whatever kernel you want if the > > > >> > current one doesn't work. > > > >> > > > >> I can't do that remotely though. I'm probably asking for > > > >> something that doesn't exist. > > > >> > > > >> - Grant > > > >> > > > > > > > > Don't do that if you don't have some tool like KVM, or other > > > > remote management of the server. Or if it is available in the > > > > data center, just call them and order this service for the time > > > > you need to do updates. > > > > > > > > This is why I don't use gentoo on servers any more, just because > > > > I rather stay safe than sorry. > > > > > > How is another distro different in this situation? > > > > > > - Grant > > > > Just because when using distros like Centos/RHEL or Debian stable, > > you have very little chance that the kernel released will fail. Due > > to extensive testing, user base and update policy. And major kernel > > update you done only once in few years and the transition is tested > > before release done (though you are supposed to test yourself to be > > safe). > > > > This is not saying that gentoo is bad, I'm very big fan of gentoo. > > But you have to concern where it use and where not. > > > > Robert. > > > > Anecdotal, but... > > I once had an Ubuntu VM that can't shutdown after a kernel update. > First boot after update went well, but when I rebooted it again, it > pegged its vCPUs at 100% before I ordered the Xen hypervisor to put > it out of its misery. I don't want to start flame, but ubuntu was never a system for server for me. It may be good for desktop, but not server. For me ubuntu is too up-to-date to be a good server distro, even the LTS is not something well done, maybe in version x.x.3-4 of LTS it s reasonable to put on server, but it will soon end with support. So nothing for me. > > The bug was apparently in the portion of the kernel running in the > primary CPU that's responsible for shutting down the other CPUs > before cutting the power. And IIRC, this bug affects all > multi-processor configuration. > > So, as you can see, binary distros can still fuck up royal time. Not > to mention that if you have an exotic configuration, support for your > configuration might not be built into the kernel by the distro. > This is true, but you cannot compare countless options that gentoo can be configured with few options that binary distro is capable and thus more probably tested before. > Somehow I believe people deploying Gentoo servers will be much more > careful... Agree. But real word is not so ideal. I got situations where I need upgrade basic gentoo server to more special virtualized environment. Just a customer wanted that. This consist about changing net to bridge, add/update kernel modules, etc. I ended with bricked server after a long checks etc, so I have to check the server physicaly. I did another thing in debian remotely within a half hour. This also implies that I'm not so good admin, but things happen not so good as you expect every time. I still use gentoo on my notebook and work computer, or specialized project where it benefits. But all the servers are migrated to debian or centos. I just don't have so much time to play. Robert. > > Rgds,
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Feb 26, 2012 2:05 AM, "Robert David" wrote: > > V Sat, 25 Feb 2012 10:32:20 -0800 > Grant napsáno: > > > >> >> I need to test a kernel config change on a remote system. Is > > >> >> there a safe way to do this? The fallback thing in grub has > > >> >> never worked for me. When does that ever work? > > >> > > > >> > > > >> > You can press ESC in the Grub screen and it will take you to > > >> > text-only mode. There, you select an entry, press "e" and edit > > >> > it. Press ENTER when you're finished, and then press "b" to boot > > >> > your modified entry. > > >> > > > >> > That way, you can boot whatever kernel you want if the current > > >> > one doesn't work. > > >> > > >> I can't do that remotely though. I'm probably asking for something > > >> that doesn't exist. > > >> > > >> - Grant > > >> > > > > > > Don't do that if you don't have some tool like KVM, or other remote > > > management of the server. Or if it is available in the data center, > > > just call them and order this service for the time you need to do > > > updates. > > > > > > This is why I don't use gentoo on servers any more, just because > > > I rather stay safe than sorry. > > > > How is another distro different in this situation? > > > > - Grant > > Just because when using distros like Centos/RHEL or Debian stable, you > have very little chance that the kernel released will fail. Due to > extensive testing, user base and update policy. And major kernel update > you done only once in few years and the transition is tested before > release done (though you are supposed to test yourself to be safe). > > This is not saying that gentoo is bad, I'm very big fan of gentoo. > But you have to concern where it use and where not. > > Robert. > Anecdotal, but... I once had an Ubuntu VM that can't shutdown after a kernel update. First boot after update went well, but when I rebooted it again, it pegged its vCPUs at 100% before I ordered the Xen hypervisor to put it out of its misery. The bug was apparently in the portion of the kernel running in the primary CPU that's responsible for shutting down the other CPUs before cutting the power. And IIRC, this bug affects all multi-processor configuration. So, as you can see, binary distros can still fuck up royal time. Not to mention that if you have an exotic configuration, support for your configuration might not be built into the kernel by the distro. Somehow I believe people deploying Gentoo servers will be much more careful... Rgds,
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> >> >> I need to test a kernel config change on a remote system. Is >> >> >> there a safe way to do this? The fallback thing in grub has >> >> >> never worked for me. When does that ever work? >> >> > >> >> > >> >> > You can press ESC in the Grub screen and it will take you to >> >> > text-only mode. There, you select an entry, press "e" and edit >> >> > it. Press ENTER when you're finished, and then press "b" to boot >> >> > your modified entry. >> >> > >> >> > That way, you can boot whatever kernel you want if the current >> >> > one doesn't work. >> >> >> >> I can't do that remotely though. I'm probably asking for something >> >> that doesn't exist. >> >> >> >> - Grant >> >> >> > >> > Don't do that if you don't have some tool like KVM, or other remote >> > management of the server. Or if it is available in the data center, >> > just call them and order this service for the time you need to do >> > updates. >> > >> > This is why I don't use gentoo on servers any more, just because >> > I rather stay safe than sorry. >> >> How is another distro different in this situation? >> >> - Grant > > Just because when using distros like Centos/RHEL or Debian stable, you > have very little chance that the kernel released will fail. Due to > extensive testing, user base and update policy. And major kernel update > you done only once in few years and the transition is tested before > release done (though you are supposed to test yourself to be safe). Yuck. :) > This is not saying that gentoo is bad, I'm very big fan of gentoo. > But you have to concern where it use and where not. > > Robert. Understood, thank you. - Grant
Re: [gentoo-user] Re: Safe way to test a new kernel?
V Sat, 25 Feb 2012 10:32:20 -0800 Grant napsáno: > >> >> I need to test a kernel config change on a remote system. Is > >> >> there a safe way to do this? The fallback thing in grub has > >> >> never worked for me. When does that ever work? > >> > > >> > > >> > You can press ESC in the Grub screen and it will take you to > >> > text-only mode. There, you select an entry, press "e" and edit > >> > it. Press ENTER when you're finished, and then press "b" to boot > >> > your modified entry. > >> > > >> > That way, you can boot whatever kernel you want if the current > >> > one doesn't work. > >> > >> I can't do that remotely though. I'm probably asking for something > >> that doesn't exist. > >> > >> - Grant > >> > > > > Don't do that if you don't have some tool like KVM, or other remote > > management of the server. Or if it is available in the data center, > > just call them and order this service for the time you need to do > > updates. > > > > This is why I don't use gentoo on servers any more, just because > > I rather stay safe than sorry. > > How is another distro different in this situation? > > - Grant Just because when using distros like Centos/RHEL or Debian stable, you have very little chance that the kernel released will fail. Due to extensive testing, user base and update policy. And major kernel update you done only once in few years and the transition is tested before release done (though you are supposed to test yourself to be safe). This is not saying that gentoo is bad, I'm very big fan of gentoo. But you have to concern where it use and where not. Robert. > > > > But if you really need to do that (and you don't have any chance to > > get KVM attached), just create an virtual machine with backup of > > your server and test that kernel there, and check that you have all > > the modules you need on the server. But this is the last thing I > > would do. > > > > > > Good luck, > > Robert. >
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> I need to test a kernel config change on a remote system. Is there a >> safe way to do this? The fallback thing in grub has never worked for >> me. When does that ever work? > > You can press ESC in the Grub screen and it will take you to text-only >>> >>> mode. >>> > There, you select an entry, press "e" and edit it. Press ENTER when >>> >>> you're >>> > finished, and then press "b" to boot your modified entry. > > That way, you can boot whatever kernel you want if the current one >>> >>> doesn't >>> > work. I can't do that remotely though. I'm probably asking for something that doesn't exist. - Grant >>> >>> Situations like these that made me decide with great conviction to always >>> deploy my servers virtualized, even if the box in question will only host a >>> single VM. >>> >>> Now, if I lost my intelligence for a couple of seconds and somehow ended up >>> with a VM that's no longer accessible remotely, I just connect to the >>> virtual console. >>> >>> The flip side? Now I'm getting too daring/careless, and the uptime now >>> drops below my (self-imposed) target of 99.99% :-P >> >> What do you do when you need to upgrade the host, rather than the guest? >> > > I think setting up a VM on the server using the new kernel should help > test a new kernel? > > -- > Nilesh Govindarajan > http://nileshgr.com I haven't used a virtualized OS in awhile but the last time I did the hardware interacting with the virtualized OS was also virtualized and wasn't representative of the actual hardware. I don't think I can test the interaction between a kernel and my actual hardware from a virtual OS. - Grant
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> > >> I need to test a kernel config change on a remote system. Is there a >> > >> safe way to do this? The fallback thing in grub has never worked for >> > >> me. When does that ever work? >> > > >> > > You can press ESC in the Grub screen and it will take you to text-only >> >> mode. >> >> > > There, you select an entry, press "e" and edit it. Press ENTER when >> >> you're >> >> > > finished, and then press "b" to boot your modified entry. >> > > >> > > That way, you can boot whatever kernel you want if the current one >> >> doesn't >> >> > > work. >> > >> > I can't do that remotely though. I'm probably asking for something >> > that doesn't exist. >> > >> > - Grant >> >> Situations like these that made me decide with great conviction to always >> deploy my servers virtualized, even if the box in question will only host a >> single VM. >> >> Now, if I lost my intelligence for a couple of seconds and somehow ended up >> with a VM that's no longer accessible remotely, I just connect to the >> virtual console. >> >> The flip side? Now I'm getting too daring/careless, and the uptime now >> drops below my (self-imposed) target of 99.99% :-P > > What do you do when you need to upgrade the host, rather than the guest? > > -- > Regards, > Mick Exactly. - Grant
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> >> I need to test a kernel config change on a remote system. Is >> >> there a safe way to do this? The fallback thing in grub has never >> >> worked for me. When does that ever work? >> > >> > >> > You can press ESC in the Grub screen and it will take you to >> > text-only mode. There, you select an entry, press "e" and edit it. >> > Press ENTER when you're finished, and then press "b" to boot your >> > modified entry. >> > >> > That way, you can boot whatever kernel you want if the current one >> > doesn't work. >> >> I can't do that remotely though. I'm probably asking for something >> that doesn't exist. >> >> - Grant >> > > Don't do that if you don't have some tool like KVM, or other remote > management of the server. Or if it is available in the data center, > just call them and order this service for the time you need to do > updates. > > This is why I don't use gentoo on servers any more, just because > I rather stay safe than sorry. How is another distro different in this situation? - Grant > But if you really need to do that (and you don't have any chance to > get KVM attached), just create an virtual machine with backup of your > server and test that kernel there, and check that you have all the > modules you need on the server. But this is the last thing I would do. > > > Good luck, > Robert.
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> I need to test a kernel config change on a remote system. Is there a >> safe way to do this? The fallback thing in grub has never worked for >> me. When does that ever work? > > > Oh crap, you said "remote system". Somehow I missed that. Ignore my > previous post since obviously accessing Grub on a remote machine would > require a hardware VNC module (if you had that, then you wouldn't have > posted about the issue in the first place, I assume.) > > The way I dealt with it, is to use the "boot once" functionality of Grub: > > http://weichong78.blogspot.com/2007/04/grub-test-kernel-once.html Perfect! That's exactly what I need. Here is an alternate method too: http://fabbritech.blogspot.com/2009/07/make-grub-boot-something-once.html I will test this ASAP. - Grant
Re: [gentoo-user] Re: Safe way to test a new kernel?
Hello, Nikos. On Sat, Feb 25, 2012 at 04:10:10AM +0200, Nikos Chantziaras wrote: > On 25/02/12 04:00, Grant wrote: > > I need to test a kernel config change on a remote system. Is there a > > safe way to do this? The fallback thing in grub has never worked for > > me. When does that ever work? > Oh crap, you said "remote system". Somehow I missed that. Ignore my > previous post since obviously accessing Grub on a remote machine would > require a hardware VNC module (if you had that, then you wouldn't have > posted about the issue in the first place, I assume.) > The way I dealt with it, is to use the "boot once" functionality of Grub: > http://weichong78.blogspot.com/2007/04/grub-test-kernel-once.html > I didn't bother with the panic handler, since I had remote hard-reset > functionality (I recommend it; it can save your day.) What is this "remote hard-reset functionality", if you don't mind me asking? Do you mean somebody on the far end of a telephone line? -- Alan Mackenzie (Nuremberg, Germany).
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Feb 25, 2012 7:22 PM, "Mick" wrote: > > On Saturday 25 Feb 2012 02:32:49 Pandu Poluan wrote: > > On Feb 25, 2012 9:14 AM, "Grant" wrote: > > > >> I need to test a kernel config change on a remote system. Is there a > > > >> safe way to do this? The fallback thing in grub has never worked for > > > >> me. When does that ever work? > > > > > > > > You can press ESC in the Grub screen and it will take you to text-only > > > > mode. > > > > > > There, you select an entry, press "e" and edit it. Press ENTER when > > > > you're > > > > > > finished, and then press "b" to boot your modified entry. > > > > > > > > That way, you can boot whatever kernel you want if the current one > > > > doesn't > > > > > > work. > > > > > > I can't do that remotely though. I'm probably asking for something > > > that doesn't exist. > > > > > > - Grant > > > > Situations like these that made me decide with great conviction to always > > deploy my servers virtualized, even if the box in question will only host a > > single VM. > > > > Now, if I lost my intelligence for a couple of seconds and somehow ended up > > with a VM that's no longer accessible remotely, I just connect to the > > virtual console. > > > > The flip side? Now I'm getting too daring/careless, and the uptime now > > drops below my (self-imposed) target of 99.99% :-P > > What do you do when you need to upgrade the host, rather than the guest? > Since I'm using XenServer, upgrading the host is a well-defined procedure: Either I push the update using XenCenter, or I visit the servers. Usually, I just push minor updates using XenCenter. Rgds,
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Sat, Feb 25, 2012 at 12:26 AM, Dale wrote: > Grant wrote: > >>> I need to test a kernel config change on a remote system. Is there a > >>> safe way to do this? The fallback thing in grub has never worked for > >>> me. When does that ever work? > >> > >> > >> You can press ESC in the Grub screen and it will take you to text-only > mode. > >> There, you select an entry, press "e" and edit it. Press ENTER when > you're > >> finished, and then press "b" to boot your modified entry. > >> > >> That way, you can boot whatever kernel you want if the current one > doesn't > >> work. > > > > I can't do that remotely though. I'm probably asking for something > > that doesn't exist. > > > > - Grant > > > > > > > There is a couple people on here that handle remote machines. I'd be > shocked if there isn't a way to do this. Just give them a bit to see > the thread. I vaguely recall someone mentioning this but since my > remote machine is about 20 feet away, I didn't make notes. > > Dale > > :-) :-) > > -- > I am only responsible for what I said ... Not for what you understood or > how you interpreted my words! > > Miss the compile output? Hint: > EMERGE_DEFAULT_OPTS="--quiet-build=n" > That's right, there are many embedded machines out there with upgrades once in a while. Perhaps you would get better results asking at gentoo-embedded list. Francisco
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Sat 25 Feb 2012 05:48:49 PM IST, Mick wrote: > On Saturday 25 Feb 2012 02:32:49 Pandu Poluan wrote: >> On Feb 25, 2012 9:14 AM, "Grant" wrote: > I need to test a kernel config change on a remote system. Is there a > safe way to do this? The fallback thing in grub has never worked for > me. When does that ever work? You can press ESC in the Grub screen and it will take you to text-only >> >> mode. >> There, you select an entry, press "e" and edit it. Press ENTER when >> >> you're >> finished, and then press "b" to boot your modified entry. That way, you can boot whatever kernel you want if the current one >> >> doesn't >> work. >>> >>> I can't do that remotely though. I'm probably asking for something >>> that doesn't exist. >>> >>> - Grant >> >> Situations like these that made me decide with great conviction to always >> deploy my servers virtualized, even if the box in question will only host a >> single VM. >> >> Now, if I lost my intelligence for a couple of seconds and somehow ended up >> with a VM that's no longer accessible remotely, I just connect to the >> virtual console. >> >> The flip side? Now I'm getting too daring/careless, and the uptime now >> drops below my (self-imposed) target of 99.99% :-P > > What do you do when you need to upgrade the host, rather than the guest? > I think setting up a VM on the server using the new kernel should help test a new kernel? -- Nilesh Govindarajan http://nileshgr.com
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Saturday 25 Feb 2012 02:32:49 Pandu Poluan wrote: > On Feb 25, 2012 9:14 AM, "Grant" wrote: > > >> I need to test a kernel config change on a remote system. Is there a > > >> safe way to do this? The fallback thing in grub has never worked for > > >> me. When does that ever work? > > > > > > You can press ESC in the Grub screen and it will take you to text-only > > mode. > > > > There, you select an entry, press "e" and edit it. Press ENTER when > > you're > > > > finished, and then press "b" to boot your modified entry. > > > > > > That way, you can boot whatever kernel you want if the current one > > doesn't > > > > work. > > > > I can't do that remotely though. I'm probably asking for something > > that doesn't exist. > > > > - Grant > > Situations like these that made me decide with great conviction to always > deploy my servers virtualized, even if the box in question will only host a > single VM. > > Now, if I lost my intelligence for a couple of seconds and somehow ended up > with a VM that's no longer accessible remotely, I just connect to the > virtual console. > > The flip side? Now I'm getting too daring/careless, and the uptime now > drops below my (self-imposed) target of 99.99% :-P What do you do when you need to upgrade the host, rather than the guest? -- Regards, Mick signature.asc Description: This is a digitally signed message part.
Re: [gentoo-user] Re: Safe way to test a new kernel?
V Fri, 24 Feb 2012 18:08:43 -0800 Grant napsáno: > >> I need to test a kernel config change on a remote system. Is > >> there a safe way to do this? The fallback thing in grub has never > >> worked for me. When does that ever work? > > > > > > You can press ESC in the Grub screen and it will take you to > > text-only mode. There, you select an entry, press "e" and edit it. > > Press ENTER when you're finished, and then press "b" to boot your > > modified entry. > > > > That way, you can boot whatever kernel you want if the current one > > doesn't work. > > I can't do that remotely though. I'm probably asking for something > that doesn't exist. > > - Grant > Don't do that if you don't have some tool like KVM, or other remote management of the server. Or if it is available in the data center, just call them and order this service for the time you need to do updates. This is why I don't use gentoo on servers any more, just because I rather stay safe than sorry. But if you really need to do that (and you don't have any chance to get KVM attached), just create an virtual machine with backup of your server and test that kernel there, and check that you have all the modules you need on the server. But this is the last thing I would do. Good luck, Robert.
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Feb 25, 2012 9:14 AM, "Grant" wrote: > > >> I need to test a kernel config change on a remote system. Is there a > >> safe way to do this? The fallback thing in grub has never worked for > >> me. When does that ever work? > > > > > > You can press ESC in the Grub screen and it will take you to text-only mode. > > There, you select an entry, press "e" and edit it. Press ENTER when you're > > finished, and then press "b" to boot your modified entry. > > > > That way, you can boot whatever kernel you want if the current one doesn't > > work. > > I can't do that remotely though. I'm probably asking for something > that doesn't exist. > > - Grant > Situations like these that made me decide with great conviction to always deploy my servers virtualized, even if the box in question will only host a single VM. Now, if I lost my intelligence for a couple of seconds and somehow ended up with a VM that's no longer accessible remotely, I just connect to the virtual console. The flip side? Now I'm getting too daring/careless, and the uptime now drops below my (self-imposed) target of 99.99% :-P Rgds,
Re: [gentoo-user] Re: Safe way to test a new kernel?
Grant wrote: >>> I need to test a kernel config change on a remote system. Is there a >>> safe way to do this? The fallback thing in grub has never worked for >>> me. When does that ever work? >> >> >> You can press ESC in the Grub screen and it will take you to text-only mode. >> There, you select an entry, press "e" and edit it. Press ENTER when you're >> finished, and then press "b" to boot your modified entry. >> >> That way, you can boot whatever kernel you want if the current one doesn't >> work. > > I can't do that remotely though. I'm probably asking for something > that doesn't exist. > > - Grant > > There is a couple people on here that handle remote machines. I'd be shocked if there isn't a way to do this. Just give them a bit to see the thread. I vaguely recall someone mentioning this but since my remote machine is about 20 feet away, I didn't make notes. Dale :-) :-) -- I am only responsible for what I said ... Not for what you understood or how you interpreted my words! Miss the compile output? Hint: EMERGE_DEFAULT_OPTS="--quiet-build=n"
Re: [gentoo-user] Re: Safe way to test a new kernel?
On Fri, Feb 24, 2012 at 9:08 PM, Grant wrote: >>> I need to test a kernel config change on a remote system. Is there a >>> safe way to do this? The fallback thing in grub has never worked for >>> me. When does that ever work? >> >> >> You can press ESC in the Grub screen and it will take you to text-only mode. >> There, you select an entry, press "e" and edit it. Press ENTER when you're >> finished, and then press "b" to boot your modified entry. >> >> That way, you can boot whatever kernel you want if the current one doesn't >> work. > > I can't do that remotely though. I'm probably asking for something > that doesn't exist. What's the nature of the remote box? For example, I have a xen vps for which I can access the console via ssh to the xen host machine. I can get at the grub menu that way. I think grub supports serial consoles, but I don't know... -- :wq
Re: [gentoo-user] Re: Safe way to test a new kernel?
>> I need to test a kernel config change on a remote system. Is there a >> safe way to do this? The fallback thing in grub has never worked for >> me. When does that ever work? > > > You can press ESC in the Grub screen and it will take you to text-only mode. > There, you select an entry, press "e" and edit it. Press ENTER when you're > finished, and then press "b" to boot your modified entry. > > That way, you can boot whatever kernel you want if the current one doesn't > work. I can't do that remotely though. I'm probably asking for something that doesn't exist. - Grant
