Re: EFI PXE boot using grubx64.efi - Large images

[Locane]

Randy you are an amazing human being - I'm working on setting this up and
trying it right now (even before your summary response) - I will let
everyone know how it goes!

On Fri, Dec 29, 2017 at 12:27 PM, Randy Goldenberg <
address@hidden> wrote:

> tl;dr:
>
> Use the kernel and initrd at centos/7.4.1708/os/x86_64/images/pxeboot.
>
> Get the squashfs root file system from the ISO, in LiveCD.
>
> Use the following boot environment:
>
> vmlinuz initrd=initrd.img ip=dhcp root=live:http://you.know.wher
> e.to.go/to/get/to/squashfs.img rootfstype=auto ro rd.live.image quiet
> rhgb rd.luks=0 rd.md=0 rd.dm=0
>
>
>
> On Friday December 29, 2017, Randy Goldenberg wrote:
>
>> Disclaimer: For PXE booting I use iPXE, not grub. I successfully EFI
>> booted the CentOS 7.4 LiveCD using the procedure outlined below, and iPXE.
>> I would not expect PXE booting with grub to be substantially different.
>>
>> I found a CentOS 7 LiveCD that appears to be the one you're trying to
>> boot, on a CentOS mirror at centos/7.4.1708/isos/x86_64/Ce
>> ntOS-7-x86_64-LiveGNOME-1708.iso.  This is the image used.  For
>> preparing your PXE booting setup, mount the ISO.
>>
>> The initrd inside the ISO at isolinux/ does not support booting over the
>> network.  Various attempts to inject the needed drivers using dracut were
>> unsuccessful.  Instead of the kernel and initrd in the ISO, I used the
>> kernel and initrd available on CentOS mirrors at
>> centos/7.4.1708/os/x86_64/images/pxeboot.  Put these files wherever you
>> put stuff to be loaded by grub; probably your tftp directory (iPXE can
>> access these using http, much faster).
>>
>> The ISO contains a squashfs archive of the root file system used for live
>> booting, in the "LiveOS" directory.  Copy the LiveOS directory to your http
>> server.
>>
>> The ISO has a boot menu at isolinux/isolinux.cfg.  This was the model for
>> the iPXE boot entry below, tweaked a bit for loading the root file system
>> over http.  It has also been tweaked for EFI booting, by adding the name of
>> the kernel and a definition of an initrd variable to the boot environment.
>> For details on the boot options, consult the dracut manual.  I would expect
>> adjusting it to fit the conventions of grub PXE booting to be trivial:
>>
>> kernel ${boot-url}CentOS-7-x86_64-LiveGNOME-1708/vmlinuz
>> initrd ${boot-url}CentOS-7-x86_64-LiveGNOME-1708/initrd.img
>> imgargs vmlinuz initrd=initrd.img ip=dhcp root=live:${boot-url}CentOS-7-
>> x86_64-LiveGNOME-1708/squashfs.img rootfstype=auto ro rd.live.image
>> quiet  rhgb rd.luks=0 rd.md=0 rd.dm=0
>>
>> "${boot-url}" is defined elsewhere.  Replace it with the URL for the
>> files on your http or tftp server, as appropriate.
>>
>> Please let me know if you have any questions.
>>
>> Thanks,
>>
>> Randy
>>
>> On Thursday December 28, 2017, Locane wrote:
>>
>> I know that the files exist and are accessible, since they are the same
>>> files
>>> that regular legacy PXE references.  That root= parameter is in the
>>> legacy PXE
>>> menu entry too.
>>>
>>> Here's the legacy PXE menu entry that works if you're curious:
>>>
>>> LABEL LiveCD
>>>         kernel /images/LiveCD/vmlinuz
>>>         MENU LABEL ^LiveCD
>>>         append initrd=/images/LiveCD/initrd.img ksdevice=bootif
>>> root=live:/
>>> boot.iso kssendmac text  ks=http://<SERVER
>>> IP>/cblr/svc/op/ks/profile/LiveCD
>>>         ipappend 2
>>>
>>> On Thu, Dec 28, 2017 at 12:12 PM, Locane <address@hidden> wrote:
>>>
>>>   The grub entry looks like this currently:
>>>
>>>   menuentry 'Do not use broken livecd' {
>>>      linuxefi images/LiveCD/vmlinuz initrd=images/LiveCD/initrd.img
>>> ksdevice=
>>>   bootif lang=  root=live:/boot.iso kssendmac text  ks=http://<SERVER
>>> IP>/
>>>   cblr/svc/op/ks/profile/LiveCD
>>>      initrdefi images/LiveCD/initrd.img
>>>   }
>>>
>>>   On Thu, Dec 28, 2017 at 12:09 PM, Randy Goldenberg <
>>>   address@hidden> wrote:
>>>
>>>       On Wednesday December 27, 2017, Locane wrote:
>>>
>>>           Hello all!  I hope this is the appropriate list for Grub2
>>>           questions, if not
>>>           please let me know.
>>>
>>>           As a self-taught DevOps person, I'm missing some knowledge.
>>>
>>>           At the moment, I'm trying to boot a 1.2 gigabyte CentOS 7.4
>>> livecd
>>>           from an
>>>           EFI PXE menu using grubx64.efi, and I'm running in to the error
>>>           "Cannot
>>>           allocate initrd".
>>>
>>>
>>>       How have you configured grub for booting the live CD?
>>>
>>>       Thanks,
>>>
>>>       Randy
>>>
>>>       _______________________________________________
>>>       Help-grub mailing list
>>>       address@hidden
>>>       https://lists.gnu.org/mailman/listinfo/help-grub
>>>
>>>
>>>
>>>
>>>