[gentoo-server] Pure-initramfs boot

[gentoo-server] Pure-initramfs boot

[Peter Abrahamsen]

[-- Attachment #1: Type: text/plain, Size: 594 bytes --]

Hi all,

I got the crazy idea to boot my servers purely from netboot with their root
filesystems being initramfs archives coming from tftp on pxeboot.

Is this reasonable? I tried just passing a cpio of my desired root partition
as the initrd option, but it ended up using my hdd as root, I think because
my initramfs didn't have a file at /init. Everyone else seems to just use
their initramfs in order to boot something else, like nfs, but I've got
plenty of RAM and don't really want to introduce the additional complexity
and latency of NFS.

Anyone done anything like that?

Thanks,
Peter

[-- Attachment #2: Type: text/html, Size: 659 bytes --]

Re: [gentoo-server] Pure-initramfs boot

[Peter Abrahamsen]

[-- Attachment #1: Type: text/plain, Size: 1541 bytes --]

(Cc: list for posterity)

Nice, thanks!

I should have waited to send the message - I made a /init that exec's
/sbin/init (maybe I can just symlink them?), removed any auto lines from
/etc/fstab, and it worked like a charm.

This is flippin' sweet. I can netboot into a re-imager, netboot into a
rescue system, netboot into a BIOS updater (if I dare), netboot into a
security thingie, or netboot a diskless webhead, just by changing a symlink
and rebooting the target system (with IPMI if necessary).

Thanks for the pointer to ThinStation, by the way, that looks really
instructional, a cool project, and maybe useful at home.

Cheers,
Peter

On Mon, Oct 20, 2008 at 6:01 PM, Stanley Brinkerhoff <stan@vtwireless.com>wrote:

> I use ThinStation on ~50 thin client PC's which operates as you describe.
>
> Stan
>
>
> On Mon, Oct 20, 2008 at 8:49 PM, Peter Abrahamsen <rainhead@gmail.com>wrote:
>
>> Hi all,
>>
>> I got the crazy idea to boot my servers purely from netboot with their
>> root filesystems being initramfs archives coming from tftp on pxeboot.
>>
>> Is this reasonable? I tried just passing a cpio of my desired root
>> partition as the initrd option, but it ended up using my hdd as root, I
>> think because my initramfs didn't have a file at /init. Everyone else seems
>> to just use their initramfs in order to boot something else, like nfs, but
>> I've got plenty of RAM and don't really want to introduce the additional
>> complexity and latency of NFS.
>>
>> Anyone done anything like that?
>>
>> Thanks,
>> Peter
>>
>
>

[-- Attachment #2: Type: text/html, Size: 2182 bytes --]

Re: [gentoo-server] Pure-initramfs boot

[Karl Holz]

I would like to try to build something like that for ppc and net  
booting it, I have a lot of ram too

Peter where you thinking of writing a script to build the root system?

If you want to start a project I'm down, I know bash, perl and php.

Peace,

Karl


On 20-Oct-08, at 20:49, "Peter Abrahamsen" <rainhead@gmail.com> wrote:

> Hi all,
>
> I got the crazy idea to boot my servers purely from netboot with  
> their root filesystems being initramfs archives coming from tftp on  
> pxeboot.
>
> Is this reasonable? I tried just passing a cpio of my desired root  
> partition as the initrd option, but it ended up using my hdd as  
> root, I think because my initramfs didn't have a file at /init.  
> Everyone else seems to just use their initramfs in order to boot  
> something else, like nfs, but I've got plenty of RAM and don't  
> really want to introduce the additional complexity and latency of NFS.
>
> Anyone done anything like that?
>
> Thanks,
> Peter

Re: [gentoo-server] Pure-initramfs boot

[Peter Abrahamsen]

Karl,

I've built a custom stage4 with catalyst based on a recent portage  
snapshot, including several tools I want to use in any environment I  
boot into (netcat, rsync, vim, less, zsh, gentoolkit, etc). I've also  
built a custom minimal install cd based on that stage4 and a 2.6.25-r7  
kernel (now with less data corruption!).

I'll probably develop an overlay for the stage4 (though not, I  
suppose, the cd) that takes the hostname from DHCP and decides what to  
do. I don't know, I haven't thought through this really clearly yet.

All our systems still have harddrives, so I think what might be most  
useful to me is to boot into something that simply mounts the local  
filesystems, an rsync's down any changes to the golden image on my  
boot server. I tried using Puppet for system configuration management  
for a while, but it will never offer the degree of control and  
precision that the system I'm proposing would, and the degree  
abstraction it offers isn't worth the complexity that comes with it.

I do plan on making a repo on github to share what I come up with. It  
isn't much yet, but could prove useful to someone.

I'll send a message when I've done so; ping me if you haven't heard  
anything by the end of the week (and care).

Cheers,
Peter

On Oct 20, 2008, at 6:44 PM, Karl Holz wrote:

> I would like to try to build something like that for ppc and net  
> booting it, I have a lot of ram too
>
> Peter where you thinking of writing a script to build the root system?
>
> If you want to start a project I'm down, I know bash, perl and php.
>
> Peace,
>
> Karl