ipxe wimboot RAM payload issue (512 MB)

[oblivionv]

Hi friends,

I have an existing pxelinux infrastructure in place. I have been using gpxelinux.0 with memdisk to boot winpe 3.0 images into memory to start windows installations. I heard about ipxe as an alternative to memdisk, in that ipxe/winboot can save RAM space. But unfortunately it isnt working as expected. I tried installing windows 7 on 512 MB RAM machine and it doesnt allow because of the same payload memdisk used to take.

For eg, if the WINPE wim is 150 MB in size, it takes the payload as

512 - 150 = 362

362 MB of RAM is not good enough for windows 7 installation and it fails saying "insufficient RAM". Now as per the ipxe/wimboot documentation, "wimboot is a boot loader for Windows Imaging Format (.wim) files. It enables you to boot a Windows PE (WinPE) environment from a RAM disk, without wasting the memory used for the RAM disk image. "

Have i understood this wrong, or is there a configurational change necessary? Here is my boot.ipxe file:-

#!ipxe
#dhcp net0 && echo IP address: ${net0/ip} ; echo Subnet mask: ${net0/netmask}
kernel http://172.16.16.16/win7/wimboot
initrd bootmgr.exe bootmgr.exe
initrd boot/bcd BCD
initrd boot/boot.sdi boot.sdi
initrd sources/boot.wim boot.wim
imgstat
boot

Am i missing anything? Kindly help.

Thank you!