[syslinux] Problem with 90MB Initrd

[Patrick Masotta]

>>>
 > What do you observe?  Does it transfer the file then the Linux kernel
 > crashes?  Does it spontaneously reboot before completing the
 > operation?
 The client is a VSphere VM Client. It displayes the IP Address and
 then:
 Loading Kernel..... ok
 Loading initrd.bz2...
 
 This stalls for minutes and the client reboots afterwards.
<<<

I have seen this before; Are you using VMware 12 ?
try changing the virtual driver.
I have reported a bug on certain VMware drivers that
mistakenly set TFTP blocksize to 1486 instead of 1468,
That leads to IP fragmentation and high chances of an aborted
TFTP transfer if the file is big. See here:
https://communities.vmware.com/message/2536960
A Wireshark traffic capture will confirm if you are suffering 
this VMware bug

VMware is lately having some issues with TFTP transfers,
This is another reported bug that produces extremely 
low speed TFTP transfers under EFI; this could also lead
to aborted transfers if the file is big.
https://communities.vmware.com/message/2536774

Best,
Patrick