PXEBOOT/TFTPBOOT + big MD_ROOT problem

[Kövesdán Gábor]

Marc Olzheim wrote:

>On Tue, Apr 19, 2005 at 09:52:07AM +0200, Emmanuel Chriqui wrote:
>  
>
>>Hi, 
>>
>>I'm trying to make very big MD_ROOT (300MB) sent using PXEBOOT+TFTPBOOT. No
>>NFS.
>>    
>>
>
>Any reasons for not using NFS ?
>
>  
>
>>I use i386/5.4RC2/TFTPD/PXEBOOT+TFTPBOOT . 
>>(same pb with a 5.3). 
>>
>>Am I missing something obvious? 
>>    
>>
>
>I'm not sure. tftp itself is able to handle 32MB+ files, but maybe the
>loader isn't.
>
>A workaround, no using NFS, could be to tftp a second filesystem image
>on boot and mount that from the root filesystem.
>
>Marc
>  
>
I assume that the PXE clients are diskless clients. If so, do they have 
enough memory to handle this extremely large image? As for tfpt, it uses 
UDP. UDP is usually used for transfer small datagrams, for instance DNS 
replies. It is also said to be an unreliable protocol. The client should 
repeat the request when no data receives. I doubt this solution is 
reliable and flexible enough. My idea for a workaround is creating a 
ramdisk from a small boot image, and transfer the less necessary 
userland binaries from the boot server to the ramdisk using normal ftp 
connection.

Cheers,

Gábor Kövesdán