Boot issues - How frequent, dangerous and hard to solve are they?

No, I’m not currently having any compromising boot issues. But over the years as I’ve used openSUSE, things happened that caused my system to stop booting and require a reinstall. Some years ago it happened because I removed a secondary hard drive… while a few years after that upgrading my openSUSE installation with the next version’s DVD did the same thing. I’m in the process of switching from Windows 7 to openSUSE, and since I’m quite paranoid about my system breaking due to some silly issue or update, I’d like to be clarified on some things. I don’t wish to lose data, or have to frequently reinstall the entire machine (which is difficult to set up properly when you have a lot of things).

The questions I have for the most part are: What packages can cause the system so stop booting? Are there specific components that might make it completely impossible to login again? Only ones I know of are the kernel and x11. I don’t know how the kernel works however, and x11 problems can easily be fixed by booting in failsafe mode or using a console to reset its configuration. It’s good to have a list, so I know what to be careful around or never mess with.

Next: When the system stops booting, how can it be fixed in a worst case scenario (without having to know a ton of fancy console commands)? Are there components that can break a system to the point where a full reinstall is the one and only option? When can you boot into a console and revert any harmful changes done to the system? Also, can the installation DVD be used to repair it without removing programs you installed, system configuration and so on? How big is the success rate of repairing with the DVD or console after any boot block? And when does --failsafe mode in GRUB stop working too? Overall, how do people who’ve had the system no longer boot solve it?

Lastly, how frequently does it happen? And what are the things you did that caused the system to not start? Did you mess with advanced parts, did you install / uninstall a normal application or library, or did the system even stop booting out of nowhere? Can simply plugging optional hardware in / out contribute? How long did it take for you to fix it, and did you lose any data in the process?

Overall, what is your experience with boot issues (in detail)? How easy are they to solve, how threatening are they? It probably varies from case to case, but it would help me to have a general overview so I know what to expect. I still tend to look at the screen whenever the system boots and go like “oh god, any second now I’m going to see a console with some errors I’ll make no sense of and have to reinstall the whole computer” (had this phobia in Windows too mind you). Would be nice if some extra info could cure it for me :stuck_out_tongue:

You don’t want to read that, do you? rotfl!

MirceaKitsune wrote:
> No, I’m not currently having any compromising boot issues. But over the
> years as I’ve used openSUSE, things happened that caused my system to
> stop booting and require a reinstall. Some years ago it happened because
> I removed a secondary hard drive… while a few years after that
> upgrading my openSUSE installation with the next version’s DVD did the
> same thing. I’m in the process of switching from Windows 7 to openSUSE,
> and since I’m quite paranoid about my system breaking due to some silly
> issue or update, I’d like to be clarified on some things. I don’t wish
> to lose data, or have to frequently reinstall the entire machine (which
> is difficult to set up properly when you have a lot of things).
>
> The questions I have for the most part are: What packages can cause the
> system so stop booting? Are there specific components that might make it
> completely impossible to login again? Only ones I know of are the kernel
> and x11. I don’t know how the kernel works however, and x11 problems can
> easily be fixed by booting in failsafe mode or using a console to reset
> its configuration. It’s good to have a list, so I know what to be
> careful around or never mess with.

I suggest a different strategy instead. It has three components:

(1) Take backups. That way, you can recover from many problems by
restoring some files or even the entire system from your backup.

(2) Have more than one installation on your computer. Specifically, have
a test system as well as your main system. Then when you want to apply
any update, or to install new software, boot your test system and apply
it first to that. Once you are happy that the test system is working,
and that you know how to resolve any problems that occurred, reboot into
your main system and apply the update.

(3) Keep multiple kernel versions. As you say, problems with the kernel
can cause serious trouble. So keep the previous, known-good version as
well as the new one that you are installing.

HTH, Dave

On 2012-09-24 11:56, MirceaKitsune wrote:
> Lastly, how frequently does it happen?

Once in ten years? :stuck_out_tongue:

I don’t really know, and my experience is no guide to others, and viceversa.


Cheers / Saludos,

Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)

Thanks for the advice. Regarding (1), I always try to keep the system backed up. I use the System Backup tool in Yast, but never tested how well it restores. Also backups of my files on external drives whenever possible. I’m hoping to find something like Macrium Reflect from Windows as well, which backs up an exact image of the partition which would theoretically be able to restore any problem (any such thing for openSUSE?)

For (2), my system is dual-boot between Windows 7 and openSUSE 12.2, and I’m not planning to install multiple Linux distros or change the partitioning. I do however have VirtualBox installed, where I can test anything experimental without worrying. I already do with some things. Only disadvantage it uses fake drivers, so I can’t experiment with anything driver related like on the real machine.

About (3), I don’t know how to keep multiple kernel versions and upgrade / downgrade between them. I only upgrade the Kernel when a new OpenSuse release does so… otherwise it would feel like badly playing with fire. But if the system can’t boot, how do you upgrade or downgrade the Kernel… or even keep multiple Kernel versions around? Does running Yast from the DVD solve anything? I doubt an official update to the Kernel could cause a system to not boot any more however… that would be really sad and scary.

On 2012-09-24 17:16, MirceaKitsune wrote:

> Thanks for the advice. Regarding (1), I always try to keep the system
> backed up. I use the System Backup tool in Yast, but never tested how
> well it restores.

Badly. It is a partial backup.

> Also backups of my files on external drives whenever
> possible. I’m hoping to find something like Macrium Reflect from Windows
> as well, which backs up an exact image of the partition which would
> theoretically be able to restore any problem (any such thing for
> openSUSE?)

dd, clonezilla…

> About (3), I don’t know how to keep multiple kernel versions

/etc/zypp/zypp.conf, search for multiversion.

> I doubt an official update to the
> Kernel could cause a system to not boot any more however… that would
> be really sad and scary.

I do not doubt. I know. I fails now and then.


Cheers / Saludos,

Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)

MirceaKitsune wrote:
> Thanks for the advice. Regarding (1), I always try to keep the system
> backed up. I use the System Backup tool in Yast, but never tested how
> well it restores. Also backups of my files on external drives whenever
> possible. I’m hoping to find something like Macrium Reflect from Windows
> as well, which backs up an exact image of the partition which would
> theoretically be able to restore any problem (any such thing for
> openSUSE?)

Check out ‘dd’

> About (3), I don’t know how to keep multiple kernel versions and
> upgrade / downgrade between them.

It’s been discussed on the forums several times so you should be able to
find details.

> But if the system can’t boot, how do you upgrade or downgrade
> the Kernel… or even keep multiple Kernel versions around?

It isn’t the kernel that does the boot. That’s done by grub. Multiple
kernels protects you against kernel faults. You use the DVD to get
around grub problems.

> I doubt an official update to the
> Kernel could cause a system to not boot any more however… that would
> be really sad and scary.

It is rare, but it does occur. The problem is that it is impossible to
test every combination of hardware, especially for every possible
configuration setting.

Thanks for the suggestions. I don’t see clonezilla in the official repositories, and neither dd (only dd_rescue, is that the one?). Does OpenSuse come with a default tool to clone partitions completely and restore cloned partitions?

As for GRUB, I thought it only takes care of showing a menu with the systems installed on that machine, then simply starting up the boot loader of each OS / partition. For OpenSuse, I thought it simply directs the system toward the kernel to start booting then grub disappears. To what point does it handle the booting? Is GRUB taking care of things up until the splash screen appears, or until the login screen shows?

As for the Kernel, I never used Zypper in the command line (just the Install Software menu in Yast). Might look later into how that works. I wonder if the Kernel is a single rpm package or a very large structure (n00b question I know).

bor@opensuse:~> which dd
/usr/bin/dd
bor@opensuse:~> rpm -qf /usr/bin/dd
coreutils-8.16-5.1.2.x86_64

Am 24.09.2012 20:56, schrieb MirceaKitsune:
> Thanks for the suggestions. I don’t see clonezilla in the official
> repositories
It is a live cd for backups
http://clonezilla.org/downloads.php


PC: oS 12.2 x86_64 | i7-2600@3.40GHz | 16GB | KDE 4.8.4 | GeForce GT 420
ThinkPad E320: oS 12.2 x86_64 | i3@2.30GHz | 8GB | KDE 4.9.1 | HD 3000
eCAFE 800: oS 12.2 i586 | AMD Geode LX 800@500MHz | 512MB | KDE 3.5.10

Ah sorry about that, I thought Clonezilla is a program. As for dd, I have coreutils installed. I tried writing dd in the console and it started working on something without printing what, so I canceled it to be safe. Will look a bit later into how it works.

Anyway, I’d still like to hear general info about how / when boot issues happen and how they are usually solved. Would take a worry off my chest lol, even after I have a good backup system running.

On 2012-09-24 23:06, MirceaKitsune wrote:
>
> Ah sorry about that, I thought Clonezilla is a program. As for dd, I
> have coreutils installed. I tried writing dd in the console and it
> started working on something without printing what, so I canceled it to
> be safe. Will look a bit later into how it works.

Careful, dd is a traditional unix type program, it works silently and obeys you instantly and
blindly, even if it means total destruction of your disk.

> Anyway, I’d still like to hear general info about how / when boot
> issues happen and how they are usually solved.

No such data exists.


Cheers / Saludos,

Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)