Re: [Devil-Linux-discuss] remote upgrade

[Serge L. <ser...@gm...>]

Andrzej,

On 08/23/2011 04:05 AM, Andrzej Odyniec wrote:
> Dears,
>
> Serge Leschinsky wrote:
>> - we have to distinguish different BEs, i.e. instead of counting on auto-search
>
> So I'm identyfying boot image using version id. This is working on my over ten remote DL
> installations. Auto-search check version on image with version on initrd. On near all instalations
> I have two or more boot devices. On each boot partition I append unique suffix to version id, i.e.
> -SD, -HD, -SSD to find proper image for boot.

So, you identify the proper image specifying the different name. OK. What about 
configs? Do you have the same trick for the configuration file?

> But boot device is selected via BIOS. so, if there is a problem with boot from one device, I
> connect to remote console via Intel AMT technology and change BIOS settings.
That's fine. I don't see any problem to have more than one boot device. However, 
I'd prefer to get the loader config files synchronized. Maybe install loader on 
RAID1.


>
>> I'd suggest using the following addition to
>> the kernel boot parameters: image=<BLOCK_DEVICE>,</PATH>,<NAME>
>> configs=<BLOCK_DEVICE>,</PATH>,<NAME>
>
> But for use kernel boot parameters, You need remote console access too.
Hmm.... Probably I don't completely understand you. Yes, to update DL I have to 
have an access to the system. Somehow. ssh or serial or SOL (serial over lan) or 
something else. In essence my idea was to modify boot loader config file every 
time I update DL - merely create an additional record there to simplify 
rollback. I suppose I'd add this records with "boot once" option, to be able to 
load the previous BE in case of inability to boot (and reset the box by power). 
However, I still need an access at least for power management.


>
>> - The only boot-loader I know (which is capable to work with UUID and
>> understands a lot of filesystem) is grub2 :).
>
> Unfortunately, Intel AMT technology use serial with semi-random i/o port, and the only boot-loader
> with possibility to set serial console i/o port is syslinux. Autodetect of this i/o port is
> complicated, and not supported via boot-loaders. In kernel this is relatively big code. Because of
> this I use syslinux only.

I don't think it's critical what loader to use. I like grub2 because it can do 
everything I need - boot from LVM, from RAID, recognize XFS and BTRFS. Text mode 
and serial console are also exist, but probably not so fully as in syslinux. I'm 
not sure if bootchain can help in your case, but nobody prevents from using 
syslinux instead on grub2.


>
>> So, in general it looks like we have a boot loader (grub2) menu, where we can
>> choose BE
>
> if we have remote access to grub menu. The only cheap method to remote access I know is Intel AMT.
> Can You suggest another?

ip-kvm, hardware serial console or SOL (aka  Intel AMT, ipmi or iLOM).


Sincerely,
Serge