Hi,
I have two SATA disc that I am intending to use as a RAID1 pair. As far as I can tell, the installation of 12.1 (x86_64) went as expected.
However, when I started to test the resilience, by setting the BIOS boot disc from SATA1 to SATA2, the boot failed with the “NO OS” message.
Switch the BIOS back again and go and have a look at the Yast2 Boot Loader Settings | Boot Loader Installation tab, and correctly enough, the “Enable Redundancy for MR Array” is set.
As conformation that the MBR’s are not the same (as I would expect them to be, due to the above switch), I ran:
#dd if=/dev/sda of=/tmp/sda-mbr.img bs=512 count=1
#dd if=/dev/sdb of=/tmp/sdb-mbr.img bs=512 count=1
Loaded each into okteta and compared them. SATA2 is different from SATA1?
What do I need to do the allow either disc to boot in the event that the gray smoke that makes these thingies work, has escaped from the other!
Regards, Martin
martinprowe wrote:
> Hi,
>
> I have two SATA disc that I am intending to use as a RAID1 pair. As far
> as I can tell, the installation of 12.1 (x86_64) went as expected.
> However, when I started to test the resilience, by setting the BIOS
> boot disc from SATA1 to SATA2, the boot failed with the “NO OS” message.
> Switch the BIOS back again and go and have a look at the Yast2 Boot
> Loader Settings | Boot Loader Installation tab, and correctly enough,
> the “Enable Redundancy for MR Array” is set.
>
> As conformation that the MBR’s are not the same (as I would expect
> them to be, due to the above switch), I ran:
>
> #dd if=/dev/sda of=/tmp/sda-mbr.img bs=512 count=1
> #dd if=/dev/sdb of=/tmp/sdb-mbr.img bs=512 count=1
>
> Loaded each into okteta and compared them. SATA2 is different from
> SATA1?
>
> What do I need to do the allow either disc to boot in the event that
> the gray smoke that makes these thingies work, has escaped from the
> other!
You don’t give details of how you have formatted the disks, set up the
RAID or set up your boot parameters, so it’s impossible to tell what you
need to do.
But it sounds like you’re just trying something, rather than having a
hard requirement for a particular configuration, in which case my
suggestion would be to stop digging in that particular hole.
It sounds like you’re hoping for some configuration that will
automatically cope with a failed boot disk. My experience is that it’s
not worth it. You’ll have to deal with the failed disk anyway, and there
are other things that can go wrong - controllers or ports, software
upgrades etc. So it won’t be a miracle cure that simplifies your life,
it will be one extra thing that you have to take care of.
I think a better solution is to boot off a single disk partition and
have another partition on a second disk as a backup boot system. Leave
the RAID for partitions that are mounted after the kernel is running.
Thank you for your thoughts…
I suspect I gave too much detail. All I wanted to do was to confirm that, what I was seeing is a bug or not.
This (Enable Redundancy for MD Array) option worked as described (see below) for me in 11.4.
In 12.1 is it conditional on some other factors that I don’t know about?
In earlier testing this option only became visible when relevant. So as it shows, I guess that something is broke as it is not writing the same boot loader code to both discs?
Lastly, this is the interactive help:
Boot Loader Type
To select whether to install a boot loader and which bootloader to install, use Boot Loader.
Boot Loader Options
To adjust options of the boot loader, such as the time-out, click Boot Loader Options.
Boot from Master Boot Record is not recommended if you have another operating system installed on your computer
**Custom Boot Partition **lets you choose a partition to boot from.
MD array is build from 2 disks. **Enable Redundancy for MD Array enable to write GRUB to MBR of both disks.
Boot Loader Installation Details
To adjust advanced boot loader installation options (such as the device mapping), click Boot Loader Installation Details.
From Other, you can manually edit the boot loader configuration files, clear the current configuration and propose
a new configuration, start from scratch, or reread the configuration saved on your disk.
If you have multiple Linux systems installed, YaST can try to find them and merge their menus.
**
Regards, Martin
martinprowe wrote:
> Thank you for your thoughts…
>
> I suspect I gave too much detail. All I wanted to do was to confirm
> that, what I was seeing is a bug or not.
> This (Enable Redundancy for MD Array) option worked as described (see
> below) for me in 11.4.
> In 12.1 is it conditional on some other factors that I don’t know
> about?
Ah, yes, you said nothing about thinking there was a bug, or that you
had previously had it working in 11.4.
I don’t use the feature, for reasons I’ve explained, and I don’t use
12.1 either. So I’m not going to be much help to you. Perhaps somebody
else will have some ideas.